Pipe fittings

Abstract

To provide a pipe joint in which the rigidity of a portion with a contact surface is improved to make a function of a projection part more reliable, and which can be constructed even when a diameter of a through hole is out of a predetermined value and small.SOLUTION: A pipe joint 11 has a female threaded part 53 that is screwed into an outer peripheral surface of a spirally corrugated pipe 13, has a contact plate 55 having a contact surface 55a brought into contact with the periphery of a through hole 73 of an underground box 71, and comprises a projection part 52 that is provided on an inner peripheral side with respect to the contact surface 55a and on the outer peripheral side with respect to the female threaded part 53, and enters the through hole 73. The pipe joint connects pipe bodies by sandwiching the periphery of the through hole 73 in cooperation with a bell mouth 12 having a male threaded part 21 screwed into an inner peripheral surface of a pipe body 13 and a contact surface 22a brought into contact with the periphery of the through hole 73. A flange-shaped annular plate part 57 is formed at an end opposite to the projection part 52, and extends in an outer peripheral direction at a distance from the contact plate 55.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a pipe joint used to connect a pipe for protecting electric wires to an underground box buried in the ground, such as a handhole or a manhole. [Background technology]

[0002] This type of pipe joint is attached to the outer periphery of a pipe inserted into a through-hole in the underground box, outside the box. The through-hole is formed by drilling a hole in the wall of the underground box, and the pipe joint has an abutment surface that abuts against the periphery of the through-hole. The pipe is connected to the through-hole by sandwiching the periphery of the through-hole between this abutment surface and a bell mouth attached to the inside of the wall at the end of the pipe.

[0003] However, the pipes buried underground are subject to earth pressure. Depending on the type of earth pressure, the pipes protruding vertically from the wall of the underground box may earth The part away from the inner box bends downward. This deformation can create a gap between the pipe fitting and the periphery of the through hole, which can make it difficult to maintain watertightness.

[0004] For this reason, the pipe body connection structure described in Patent Document 1 below was devised.

[0005] This pipe connection structure has a cylindrical protrusion that penetrates into the through hole on the inner circumferential portion of the abutment surface of the pipe fitting that abuts against the periphery of the through hole. Even if the pipe bends and the abutment surface of the pipe fitting tries to move away from the periphery of the through hole, the protrusion comes into contact with the inner circumferential surface of the through hole to prevent the pipe fitting from tilting, thereby maintaining watertightness. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6071720 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the portion having the abutment surface is a plate-like member that protrudes in the outer circumferential direction like a flange, and the portion opposite the protrusion is formed in a simple cylindrical shape. This portion should have high rigidity in order to ensure strong fastening and the function of the protrusion that prevents displacement of the pipe joint.

[0008] Furthermore, the through-holes in the underground box may not be the desired size depending on the drilling tool used. Since the diameter of the protrusions formed on the pipe joints is set to a predetermined value, if the through-hole size is too small for the protrusions, the pipe joints prepared cannot be used. Such a situation at the construction site can lead to serious problems, such as delays in construction.

[0009] Therefore, the main object of this invention is to improve the rigidity of the part having the abutment surface to make the function of the protrusion more reliable, while also achieving other advantages, such as making it possible to carry out construction even if the diameter of the through hole deviates from the specified value. [Means for solving the problem]

[0010] The means for this purpose is connected to the outer circumferential surface of the tube. Female thread and a contact plate having a contact surface that contacts the periphery of the through hole to be connected, and the Female thread a protrusion that penetrates the through hole at a position on the outer periphery of the pipe body, and is connected to the inner periphery of the pipe body; Male thread and a bell mouth having an abutment surface that abuts against the periphery of the through hole of the connection target, thereby clamping the periphery of the through hole and connecting the pipe to the through hole, wherein a flange-shaped annular plate portion that protrudes in the outer circumferential direction at a distance from the abutment plate is formed at the end opposite to the protrusion, The annular plate portion is formed to a size corresponding to the size of the abutment plate. It is a pipe fitting.

[0011] In this configuration, when the size of the through hole to be connected is a predetermined size or within the allowable range, the pipe fitting is attached to the pipe body using the coupling portion, and the protrusion is inserted into the through hole. In this state, the periphery of the through hole is sandwiched between the abutment surfaces of the pipe fitting and the bell mouth. At this time, the annular plate portion is integral with the abutment plate behind the abutment plate having the abutment surface, improving the rigidity of the portion of the abutment plate facing the annular plate portion.

[0012] Furthermore, when the size of the through hole to be connected is smaller than a predetermined value and the protrusion cannot be inserted, the annular plate portion performs a tightening function in place of the abutment plate by using the pipe fitting inverted front to back.

[0013] Furthermore, the annular plate portion extends outward in a flange-like shape, and the outer surface is positioned away from the outer surface of the connected pipe body to improve operability, and in cooperation with the abutment plate that is spaced apart even though it is plate-shaped, this makes it easier to hold that part. [Effects of the Invention]

[0014] According to this invention, a ring-shaped plate portion is provided behind the abutment plate, thereby improving the rigidity of the portion extending from the abutment plate to the ring-shaped plate portion, thereby ensuring the function of the protrusion inserted into the through hole of the connection object.

[0015] Furthermore, if the through-hole is too small to insert the protrusion, the pipe fitting can be turned over and the annular plate can be used in place of the abutment plate. In this case, the section from the annular plate to the abutment plate has high rigidity, so it can be tightened more firmly and watertightness can be maintained.

[0016] In addition, the annular plate portion that protrudes in the outer circumferential direction makes it easier to hold than if it were located closer to the outer circumferential surface of the pipe body, thereby improving the workability of installation and tightening. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. [Figure 2]FIG. 4 is a cross-sectional view showing the pipe body connection structure in a separated state. [Figure 3] Cross-sectional view of the device in use. [Figure 4] FIG. 4 is a perspective view of the pipe joint with the water-stopping material separated. [Figure 5] 1A and 1B are a front view, a side view, and a cross-sectional view of a pipe fitting. [Figure 6] FIG. [Figure 7] Cross-sectional view of the device in use. [Figure 8] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. [Figure 9] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. [Figure 10] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. [Figure 11] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. [Figure 12] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. [Figure 13] 1A and 1B are a perspective view, a front view, a side view, and a cross-sectional view of a pipe joint. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of the present invention will be described below with reference to the drawings.

[0019] Fig. 1 shows a perspective view of a pipe joint 11. As shown in Fig. 2, this pipe joint 11 is used to obtain a pipe connection structure that uses a bell mouth 12 to connect a spiral corrugated pipe 13 (hereinafter referred to as "pipe") to an underground box 71, which is the connection target.

[0020] The pipe body 13 is made of synthetic resin and is used to protect electric wires buried underground. Spiral irregularities (spiral waves) are formed on the inner surface as well as the outer surface. The pipe body 13 is connected by fitting one end into a circular through-hole 73 formed in the wall 72 of the underground box 71. In the connected state, as shown in FIG. 3, the pipe body 13 protrudes perpendicularly from the outer surface 72a of the wall 72 of the underground box 71.

[0021] The pipe fitting 11 is made of synthetic resin and is formed in a substantially cylindrical shape as shown in Figure 1, with a through-hole 11a inside through which the pipe body 13 passes. The cylindrical pipe fitting 11 can be divided into two parts in the longitudinal direction (axial direction), with one end in the axial direction being a main body part 51 and the other end being a protrusion part 52.

[0022] A female thread portion 53 is formed on the inner peripheral surface of the main body portion 51 of the pipe fitting 11 as a joining portion that is joined by screwing to the outer peripheral surface of the pipe body 13. This female thread portion 53 is provided with a sheet-like water-stopping material 54 that expands when it absorbs moisture.

[0023] The water-stopping material 54 can be a nonwoven fabric made of polyethylene terephthalate or the like that holds a water-expanding material that expands when it absorbs water. To fix the female thread portion 53, it is preferable to attach the water-stopping material 54 cut to the required shape as shown in Figure 4, but the water-stopping material 54 can also be molded integrally with the pipe fitting 11 when it is molded.

[0024] Figure 5 shows a side view, a front view, and a cross-sectional view of the pipe fitting 11, omitting all of the water-stopping materials, including the aforementioned water-stopping material 54. In Figure 5, (a) is a left side view, (b) is a front view, (c) is a right side view, and (d) is an AA cross-sectional view of (c), and the dashed line in (a) indicates the cross-sectional shape at the BB cutting position of (d).

[0025] At the end of the outer circumferential surface of main body 51 that connects to underground box 71, i.e., the end on the protrusion 52 side, there is formed a contact plate 55 that protrudes outward like a flange and has a larger diameter than through hole 73. Here, "the side that connects to underground box 71" indicates the direction in the originally intended use mode, and does not have an absolute meaning.

[0026] The abutment plate 55 is annular with a circular outline. The flat surface of the abutment plate 55 facing the protrusion 52 is the abutment surface 55a that abuts against the periphery of the through-hole 73 on the outer surface 72a of the underground box 71. The abutment surface 55a is also provided with a water-stopping material 56. Therefore, the abutment surface 55a abuts against the underground box 71 indirectly via the water-stopping material 56.

[0027] The water-stop material 56 provided on the contact surface 55a is formed in a circular ring shape. The water-stop material 56 may be composed solely of water-swellable nonwoven fabric, as described above. However, because the contact surface 55a is the part that comes into strong contact with the in-ground box 71 as it rotates, a two-layer structure with a rubber layer 56b on the back surface of the water-swellable nonwoven fabric layer 56a is preferable, as shown in Figure 4. By laminating the nonwoven fabric layer 56a on a rubber layer 56b made of soft rubber, when the water-swellable nonwoven fabric layer 56a expands to exert a tightening force, the rubber layer 56b is compressed and deformed, but still exerts a repulsive force. This results in a firm tightening force and a better water-stopping condition.

[0028] At the end of the outer periphery of the main body 51 opposite to the side connected to the underground box 71, a flange-shaped annular plate 57 is formed, projecting outward at a distance from the abutment plate 55. The meaning of "the side connected to the underground box 71" here also indicates the direction in the originally intended use mode, and does not have an absolute meaning.

[0029] The axial length of the main body 51 having the annular plate portion 57 and the abutment plate 55 is set to at least the length necessary to form the female thread portion 53, and also to a length that allows the abutment plate 55 and the annular plate portion 57 to be stabilized when the fingertips or hand are hooked on them.

[0030] The shape of the annular plate portion 57 is the same as that of the abutment plate 55, and is annular with a circular contour. The size of the annular plate portion 57 corresponds to the size of the abutment plate 55. In other words, the annular plate portion 57 is sized to match the abutment plate 55, and is formed to be the same size or similar. Even if the contour shapes of the annular plate portion 57 and the abutment plate 55 are different, they can be similar in size if part of their diameters is the same or similar.

[0031] In this example, the annular plate portion 57 is formed to have the same size and shape as the contact plate 55 and is arranged parallel to the contact plate 55 .

[0032] Ribs 58 are formed between the annular plate portion 57 and the abutment plate 55 to connect them. The ribs 58 extend parallel to the axial direction of the main body portion 51, and are arranged at equal intervals along the circumferential direction. In this example, there are four ribs 58. The height of the ribs 58 is set to a height that sufficiently supports the annular plate portion 57 and the abutment plate 55, and more preferably, to a height that allows the fingers or hand to come into contact with the outer periphery of the main body portion 51 when the fingers or hand are placed on the outer periphery.

[0033] The flat surface of the annular plate portion 57 opposite to the contact surface 55a of the contact plate 55 is the contact surface 57a when inverted, and this contact surface 57a when inverted is provided with a water stop material 59. This water stop material 59 should have the same structure as the water stop material 56 provided on the contact surface 55a of the contact plate 55. In other words, the water stop material 59 should have a two-layer structure with a rubber layer 59b on the back surface of a water-swellable nonwoven fabric layer 59a.

[0034] The aforementioned protrusion 52 is integrally formed on the end of the main body 51 on the side having the abutment plate 55, in a portion that is inner peripherally of the abutment surface 55a and outer peripherally of the female thread portion 53. This protrusion 52 is cylindrical, and is the portion that enters the through hole 73.

[0035] As shown in FIG. 6, the size of the outer peripheral surface of the protrusion 52, that is, the outer diameter D1, is set to be slightly smaller than the predetermined desired diameter D2 of the through hole 73 by about several millimeters.

[0036] The female thread portion 53 described above is not formed on this protrusion 52, and the range in which the female thread portion 53 is formed is only the range corresponding to the portion between the abutment plate 55 and the annular plate portion 57. The inner peripheral surface of the protrusion 52 has a smooth circumferential surface without any irregularities.

[0037] Although a longer length L1 of the protrusion 52 is desirable in the intended usage, it is set to be equal to or less than the thickness L2 of the wall 72 of the underground box 71. Since the contact surface 55a is provided with the water-stopping material 56, the "length L1 of the protrusion 52" referred to here is the length obtained by subtracting the thickness t of the water-stopping material 56 from the original length L3 of the protrusion 52.

[0038] The illustrated underground box 71 has a wall 72 that is thinner than usual, about 30 mm thick.

[0039] The thickness of the protrusion 52 is such that it has the desired rigidity and creates a gap between it and the outer surface of the pipe body 13 to which it is connected, regardless of the inner surface of the main body 51 (the radial position of the thread root of the female thread portion 53).

[0040] The bell mouth 12 is made of synthetic resin and has a cylindrical male threaded portion 21 as a connecting portion that is screwed onto the inner circumferential surface of the pipe body 13, and one end of this male threaded portion 21 has an annular abutment plate 22 that protrudes outward like a flange and is larger than the through hole 73. The surface of this abutment plate 22 that has the male threaded portion 21 is an abutment surface 22a that indirectly abuts against the periphery of the through hole 73 on the inner surface 72b of the underground box 71. A water-stopping material 23 is also provided on this abutment surface 22a.

[0041] The pipe body 13 can be connected to the wall portion 72 of the underground box 71 using the pipe joint 11 as described above as follows.

[0042] First, one end of the pipe body 13 is screwed onto the pipe joint 11, and the protrusion 52 of the pipe joint 11 is inserted into the through-hole 73 formed in the wall portion 72 of the underground box 71 from the outer surface 72a side.

[0043] Next, the male threaded portion 21 of the bell mouth 12 is threaded onto the inner peripheral surface of the pipe body 13 from the inner surface 72b of the wall portion 72 of the underground box 71, and the abutment surfaces 55a, 22a of the pipe fitting 11 and the bell mouth 12 clamp the periphery of the through hole 73 in the wall portion 72 in the thickness direction. In this way, the pipe fitting 11 and the bell mouth 12 cooperate to connect the pipe body 13 inside the through hole 73, and as shown in Figure 3, the pipe fitting 11 and the pipe body 13 protrude vertically from the wall portion 72. At this time, the outer peripheral surface of the protrusion 52 of the pipe fitting 11 is close to the inner peripheral surface of the through hole 73 with a thin gap between them.

[0044] The main body 51 of the pipe fitting 11 has a horizontal U-shaped cross section with flanges on both ends of the cylindrical portion, making it highly rigid and easy to hold by hand. Furthermore, the outer diameter of the annular plate 57, together with the abutment plate 55, is larger than the inner diameter, allowing the hand holding it to be kept away from the pipe body 13, facilitating rotation and efficient application of force. This improves workability when screwing the pipe fitting 11 together, facilitating the work of clamping the wall 72 of the in-ground box 71 by tightening it.

[0045] After connection and burying the pipe fitting 11 in the ground, all of the water-stopping materials 54, 56, 59 absorb moisture in the ground and expand, eliminating gaps in the water-stopping materials 54, 56, 59 and strengthening the connection between the members 11, 12, 13. The protrusion 52 of the pipe fitting 11 is maintained inserted in the through-hole 73 so that it cannot move relative to the pipe fitting 11.

[0046] In this state, even if earth pressure is applied and a load is applied that presses down on the pipe body 13 from above, causing the pipe body 13 to bend and deform, the protrusion 52 of the pipe fitting 11 will be in contact with or in a state that is quasi-contact with the inner circumferential surface of the through hole 73, preventing relative displacement. This action is also supplemented by the expansion force of the water-stopping materials 56, 23 provided on the contact surfaces 55a, 22a.

[0047] In this way, protrusion 52 prevents displacement of pipe fitting 11 within through hole 73, and also provides high rigidity to main body 51, which includes abutment plate 55 and annular plate portion 57. Therefore, even if a load that bends pipe body 13 downward is applied, abutment surface 55a of pipe fitting 11 will not be significantly displaced in a direction away from the periphery of through hole 73, and watertightness can be maintained.

[0048] The rigidity of the main body 51 is further increased by providing the rib 58 between the contact plate 55 and the annular plate 57, and since the clamping force can be increased, the above-mentioned effect can be more reliably achieved.

[0049] Furthermore, because the connecting portion between the pipe fitting 11 and the bell mouth 12 is constructed with a screw, the connection can be performed by rotation, making the connection work extremely easy. Furthermore, because the annular plate portion 57 is formed in a circular ring shape and is sized to match the size of the abutment plate 55, the main body portion 51 can be easily held and rotated with the fingertips or hand, and rotational force can be efficiently applied. Furthermore, the rib 58 acts as a non-slip device when rotating, making the work easier.

[0050] If the size of the through-hole 73 in the underground box 71 is smaller than expected and the protrusion 52 cannot be inserted, the inverted use abutment surface 57a is pressed against the outer surface 72a of the underground box 71 to connect, as shown in Figure 7. In other words, the pipe fitting 11 is used by being inverted in the opposite direction to the example shown in Figure 3 described above.

[0051] When used in this manner, the functions of the annular plate portion 57 and the abutment plate 55 are reversed, but the operation is the same. However, since the protrusion 52 does not enter the through hole 73, it is exposed to the outside of the underground box 71.

[0052] However, as described above, the main body 51 has high rigidity, so a strong fixed state can be obtained and a good watertight state can be maintained. The threading workability of the pipe joint 11 is also good as described above.

[0053] Furthermore, even if soil pressure is applied and the pipe body 13 bends downward, the inner peripheral surface of the protrusion 52 is smooth and has no irregularities, and there is a gap between it and the outer peripheral surface of the pipe body 13, so it is possible to prevent the pipe body 13 from being subjected to strong pressure due to deformation. Therefore, when the annular plate portion 57 is used in an inverted state, it is possible to prevent large displacement that would cause a gap to be created as the abutment surface 57a separates from the outer surface 72a of the underground box 71, and watertightness can be maintained.

[0054] In particular, when the length of the protrusion 52 is set short so that it can be connected to an underground box 71 having a wall 72 that is thinner than usual, such as the pipe fitting 11 in the illustrated example, it is less susceptible to deformation of the pipe body 13.

[0055] The pipe fitting 11 having the above-described configuration is available in multiple types depending on the thickness of the pipe body 13 to be connected, but not all types of pipe fittings 11 have similar shapes, and the dimensions of each part differ depending on the size.

[0056] An example of a pipe fitting 11 having different dimensions depending on the diameter will be described below with reference to Figures 8 to 13. In this description, the same components as those in the above-described configuration will be assigned the same reference numerals and detailed description thereof will be omitted.

[0057] 8 to 13 show the appearance and cross section of the pipe fitting 11, with all of the water-stopping materials 54, 56, and 59 omitted, and are shown in the same format in all figures. In the figures, (a) is a perspective view, (b) is a left side view, (c) is a front view, (d) is a right side view, and (e) is a vertical cross-sectional view at the center of the right side view. The dashed line in (a) indicates the cross-sectional shape at the position indicated by the dashed line in (e), which is the position where the threads of the female thread portion 53 are located.

[0058] Furthermore, the length of the protrusion 52 in all figures is the same as that of the protrusion 52 in Figure 5, since the thickness of the wall 72 to be connected is the same as that of the pipe joint 11 described above and shown in Figure 5.

[0059] FIG. 8 shows a pipe fitting 11 having a smaller diameter than the pipe fitting 11 of FIG. 5, and FIGS. 9 to 13 show pipe fittings 11 having diameters that are gradually increased from the pipe fitting 11 of FIG.

[0060] As shown in these figures, as the diameter increases, the length of the main body 51 increases stepwise, and the ratio of its length to the length of the protrusion 52 increases stepwise. The length of the protrusion 52 is the same for all pipe fittings 11, so the smaller the diameter, the longer and thinner the protrusion 52, and the larger the diameter, the thicker and shorter the protrusion 52.

[0061] The thickness of the water-stopping material provided on the pipe joints 11 of different sizes is the same.

[0062] The above configuration is one embodiment for carrying out the present invention, and the present invention is not limited to the above configuration, and other configurations can also be adopted.

[0063] For example, the pipe 13 may be a spirally corrugated pipe or an independent mountain type pipe. [Explanation of symbols]

[0064] 11...Pipe fitting 12...Bellmouth 13...Spiral wave tube 21...Male thread 22a...Abutment surface 52...Protrusion 53... Female thread 55...Abutting plate 55a...Abutment surface 57...Annular plate 57a...Contact surface when used in reverse 58...Rib 59...Waterproof material 71...Underground box 73...Through hole

Claims

1. a pipe fitting having a female thread portion coupled to an outer peripheral surface of a pipe body, and an abutment plate having an abutment surface that abuts against the periphery of a through hole to be connected, and a protrusion that enters the through hole at a position inner peripherally of the abutment surface and outer peripherally of the female thread portion, and having a male thread portion coupled to the inner peripheral surface of the pipe body, and cooperating with a bell mouth having an abutment surface that abuts against the periphery of the through hole to connect the pipe body to the through hole by clamping the periphery of the through hole, a flange-shaped annular plate portion is formed at the end opposite to the protrusion portion and projects outwardly from the contact plate at a distance therefrom, The annular plate portion is formed to a size corresponding to the size of the abutment plate. Pipe fittings.

2. The annular plate portion is formed in an annular shape with a circular contour.

2. The pipe fitting according to claim 1.

3. A rib is formed between the annular plate portion and the abutment plate to connect them.

3. A pipe joint according to claim 1 or claim 2.

4. The female thread portion is formed only in a range corresponding to the portion between the abutment plate and the annular plate portion. A pipe joint according to any one of claims 1 to 3.

5. A water-stopping material is provided on the surface of the annular plate portion opposite to the contact surface. A pipe joint according to any one of claims 1 to 4.

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