JP2014207752A - Pipe connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain water-stopping performance even if the earth pressure is applied, in a connection structure for connecting a pipe to be buried in the ground with a through hole made in the side face of an underground box.SOLUTION: In a pipe connection structure 11 for connecting a spirally corrugated pipe 14 with the through hole 73 of an underground box 71, by holding the periphery of the through hole 73 by a pipe joint 12 having a female screw part 21 to be screwed over the outer peripheral surface of the spirally corrugated pipe 14, and a contact surface 23a coming into contact with the periphery of the through hole 73 of an underground box 71, and a bellmouth having a male screw part 31 screwing to the inner peripheral surface of the spirally corrugated pipe 14, and a contact surface 32a coming into contact with the periphery of the through hole 73 of an underground box 71, a cylindrical protrusion 25 fitting to the through hole 73 is formed on the pipe joint 12, thus preventing the contact surface 32a of the pipe joint 12 from displacing in a direction separating from the periphery of the through hole 73.

Description

  The present invention relates to a tube connecting structure for connecting a tube for protecting an electric wire to an underground box buried in the ground such as a handhole or a manhole, and more particularly, even when earth pressure is applied. The present invention relates to a tube connecting structure capable of maintaining water.

  Examples of the tube connecting structure as described above include structures disclosed in Patent Documents 1 and 2 below.

  The pipe connection structure of Patent Document 1 includes a pipe joint having a female thread portion that is screwed onto the outer peripheral surface of a spiral wave-attached tube, and a contact surface that comes into contact with the periphery of the through hole of the underground box, and a spiral wave. With a bell mouth that has a male thread portion that is screwed to the inner peripheral surface of the attachment tube, and a contact surface that contacts the periphery of the through hole of the underground box, the periphery of the through hole is sandwiched in the thickness direction, The tubular body is connected to the through hole.

  The structure of Patent Literature 2 is a configuration in which a spiral wave tube is not directly connected to a through-hole by a pipe joint as in Patent Literature 1, but indirectly. That is, a receiving joint is connected to the pipe joint, and a spiral wave tube is connected to the receiving joint.

  In any of the structures of Patent Documents 1 and 2, the manner of attaching the pipe joint and the bell mouth to the inside of the through hole and the periphery thereof is the same. That is, the contact surface of the pipe joint and the bell mouth sandwiches the periphery of the through hole in the thickness direction, and the pipe joint, the pipe with a spiral wave or the receiving joint, and the male thread portion of the bell mouth are arranged in the through hole from the outer peripheral side, The through hole extends in the thickness direction. There is a gap between the pipe joint existing in the through hole and the inner peripheral surface of the through hole.

JP 2001-90884 A Japanese Patent No. 4961174

  However, in the connection structure as described above, since the pipe with a spiral wave and the joint and the pipe joint that supports the pipe are subjected to earth pressure when buried in the ground, the water stoppage is impaired depending on how the earth pressure is applied. There is a possibility.

  In other words, the pipe joint and the spiral wave pipe and the receiving joint protrude vertically from the side surface of the underground box, so that when the earth pressure is applied from above, the pipe joint and the spiral wave pipe and the receiving joint are separated from the underground box. It bends and deforms so that it falls downward at the part. By this bending, a gap is formed between the contact surface of the pipe joint and the periphery of the through hole. Although the contact surface includes a water expansion layer that expands when it contains moisture, if the bending deformation is large, the water stoppage cannot be maintained.

  Therefore, the main object of the present invention is to maintain the water-stopping property so as not to bend greatly even when earth pressure is applied.

  Means for this purpose include a joint that has a coupling portion that is coupled to the outer peripheral surface of the tube body, and has a contact surface that abuts around the through-hole to be connected, and a coupling portion that couples to the inner peripheral surface of the tube body And a bell mouth having an abutment surface that abuts the periphery of the through-hole to be connected, and sandwiches the periphery of the through-hole to connect the tubular body to the through-hole. In addition, the pipe connection structure includes a protrusion that enters the through-hole at a portion on the inner peripheral side of the contact surface of the pipe joint and on the outer peripheral side of the coupling portion.

  Another means has a coupling portion that couples to the outer peripheral surface of the tube body, has a contact surface that abuts around the through hole to be connected, and has a coupling portion that couples to the inner peripheral surface of the tube body A pipe joint for connecting the tubular body to the through-hole by sandwiching the circumference of the through-hole in cooperation with a bell mouth having an abutting surface that abuts the circumference of the through-hole to be connected; And a pipe joint provided with a protrusion that enters the through hole at a portion on the inner circumferential side from the contact surface and on the outer circumferential side from the coupling portion.

  In this invention, the joint part of the pipe joint is joined to the pipe body, the abutment surface of the pipe joint is brought into contact with the periphery of the through hole, and the joint part of the bell mouth is joined to the pipe body from the opposite side of the through hole. Then, contact the contact surface of the bell mouth around the through hole. When the contact surface of the pipe joint is brought into contact with the periphery of the through hole, the protrusion enters the through hole on the outer peripheral side of the tube body. The protrusion extends in the thickness direction within the through hole, and even if a load is applied to the pipe body or pipe joint to deflect them, the contact surface of the pipe joint may be displaced away from the periphery of the through hole. The protrusion comes into contact with the inner peripheral surface of the through hole and prevents its displacement.

  According to this invention, since the protrusion suppresses the bending deformation of the pipe joint in the through hole, the occurrence of a large displacement can be prevented. As a result, it is possible to avoid the formation of a gap that impairs the water stop, and to maintain the water stop.

Sectional drawing of a pipe body connection structure. The perspective view of a pipe joint, packing, and a bell mouth. Sectional drawing of the isolation | separation state of a tubular-body connection structure. The perspective view of the pipe joint which concerns on another example. Sectional drawing of the pipe | tube connection structure which concerns on another example.

An embodiment for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a tube connection structure 11. The tube connection structure 11 uses a pipe joint 12 and a bell mouth 13 to connect a tube 14 with a spiral wave (hereinafter referred to as “tube”) to the ground. It is connected to the inner box 71.

  The said pipe body 14 is for protecting the electric wire embed | buried under the ground, and is a product made from a synthetic resin. Spiral irregularities (spiral waves) are formed not only on the outer peripheral surface but also on the inner peripheral surface. This tubular body 14 is connected so as to fit one end into a through hole 73 formed in the wall 72 of the underground box 71. In the connected state, the tubular body 14 projects vertically from the outer surface of the wall portion 72 of the underground box 71.

  The pipe joint 12 is made of synthetic resin and has a substantially cylindrical shape as shown in FIG. The entire inner peripheral surface of the pipe joint 12 has a female thread portion 21 as a coupling portion that is coupled to the outer peripheral surface of the tube body 14 by screwing. The female screw portion 21 is provided with a sheet-like water blocking material 22 that expands when it contains moisture.

  A non-woven fabric made of polyethylene terephthalate or the like holding a water expansion material that absorbs moisture and expands can be used as the water stop material 22. Fixing to the female screw portion 21 may be performed by integral molding when the pipe joint 12 is molded.

  An annular contact plate 23 that protrudes like a bowl in the outer peripheral direction and is larger than the through hole 73 is located at a base end side of the outer peripheral surface of the pipe joint 12, that is, a side that is connected to the underground box 71. Is formed. The base end side surface of the contact plate 23 is a contact surface 23 a that contacts the periphery of the through hole 73 on the outer surface of the underground box 71. The abutting surface 23a is also provided with a water stop material 24 similar to the above. For this reason, the abutting surface 23 a abuts indirectly through the water blocking material 24.

  A portion closer to the base end side than the contact surface 23 a and on the inner peripheral side from the contact surface 23 a and on the outer peripheral side from the female screw portion 21 is formed in a cylindrical shape having an outer peripheral surface slightly smaller in diameter than the through hole 73. ing. This cylindrical portion is the protrusion 25 that enters the through hole 73. The female screw portion 21 is also formed on the protrusion 25. Although the length of the protrusion 25 is set as appropriate, it is desirable that the length is as long as possible.

  An annular packing 15 as shown in FIG. 2 is attached to the outer peripheral surface of the protrusion 25. This packing 15 contributes to water stoppage and prevention of slipping between the inner peripheral surface of the through hole 73.

  Protruding portions 26 having a front view shape are intermittently formed along the circumferential direction at a portion of the outer peripheral surface of the pipe joint 12 on the tip side from the contact plate 23. These protrusions 26 are portions that become caught when the pipe joint 12 is rotated when the pipe joint 12 is connected.

  The bell mouth 13 is made of synthetic resin, and has a cylindrical male screw portion 31 as a coupling portion that is coupled to the inner peripheral surface of the tube body 14 by screwing. An annular contact plate 32 that protrudes like a ring and is larger than the through hole 73 is provided. A surface of the contact plate 32 on the side having the male screw portion 31 is a contact surface 32 a that indirectly contacts the periphery of the through hole 73 on the inner surface of the underground box 71. This abutting surface 32a is also provided with a water stop material 33 similar to the above.

In the tubular body connection structure 11 composed of the members as described above, the tubular body 14 is connected as follows. First, the tubular body 14 is connected to the tubular joint 12 having the packing 15 as shown in FIG. Are inserted into the through hole 73 formed in the wall portion 72 of the underground box 71 from the outer surface.

  Next, the male thread portion 31 of the bell mouth 13 is screwed into the inner peripheral surface of the pipe body 14 from the inner side surface of the wall portion 72 of the underground box 71, and the contact surfaces 23 a and 32 a of the pipe joint 12 and the bell mouth 13 are used. The periphery of the through hole 73 of the wall portion 72 is sandwiched in the thickness direction. Then, as shown in FIG. 1, the pipe joint 12 and the pipe body 14 project vertically from the wall portion 72, and the pipe body 14 is connected in the through hole 73.

  At this time, the protrusion 25 of the pipe joint 12 is in a state of being fitted to the inner peripheral surface of the through hole 73 via the packing 15.

  Since it is in such a connection state, it has the following effects.

  The pipe joint 12 and the bell mouth 13 are coupled to the pipe body 14 via the female thread portion 21 and the male thread section 31, respectively, and the contact surfaces 23a and 32a of the pipe joint 12 and the bell mouth 13 are maintained in the coupled state. The wall 72 is sandwiched between the two. By being buried in the ground, the water-stopping materials 24 and 33 provided on the contact surfaces 23a and 32a and the water-stopping material 22 provided on the female screw portion 21 absorb the moisture in the ground and expand, and the water-stopping material. The portions 22, 24, 33 are made free of gaps, and the connection state of the members 12, 13, 14, 72 is strengthened. In the protrusion 25 of the pipe joint 12, the state of being inserted into the through hole 73 so as not to be relatively displaced is maintained.

  Even if the earth pressure is applied in this state and a load is applied to the pipe body 14 and the pipe joint 12 so as to be pressed from above, the distal end side of the pipe body 14 and the pipe joint 12 is bent and deformed. Is in contact with the inner peripheral surface of the through hole 73 or in a state corresponding to the contact, and prevents relative displacement. This action is also compensated by the expansion force of the water blocking materials 24 and 33 provided on the contact surfaces 23a and 32a.

  As described above, since the protrusion 25 prevents the displacement of the pipe joint 12 from the through hole 73, even if a load is applied to the pipe body 14 or the pipe joint 12 such that the pipe joint 12 is bent, the abutment of the pipe joint 12 can be prevented. The surface 23 a is not greatly displaced in the direction away from the periphery of the through hole 73. In particular, the protrusion 25 that is a part of the pipe joint 12 that exhibits the fixing force directly contacts the through hole 73 at a position close to the inner peripheral surface of the through hole 73 to prevent relative displacement. Compared with the case where the fixed tube body 14 is in contact with the through hole 73, the relative displacement can be prevented more effectively. For this reason, it can be avoided that a gap that impairs the water stoppage can be made unexpectedly, and the water stoppage can be ensured.

  In addition, since the coupling portion between the pipe joint 12 and the bell mouth 13 is configured by a screw, the coupling can be performed by rotating, and the connection work is very easy. Moreover, since the contact plates 23 and 32 of the pipe joint 12 and the bell mouth 13 are annular, the rotation work for the connection work can be performed smoothly.

  Other examples will be described below. In this description, parts that are the same as or equivalent to those in the above configuration are given the same reference numerals, and detailed descriptions thereof are omitted.

FIG. 4 is a perspective view of a pipe joint 12 according to another example. The protruding portion 25 of the pipe joint 12 has a cylindrical shape having no internal thread portion on the inner peripheral surface. The thickness of the protrusion 25 is appropriately set.
The pipe joint 12 having such a configuration also has the same effects as described above.

  FIG. 5 is a cross-sectional view of a tube connection structure 11 according to another example. In this tubular body connection structure 11, a receiving joint 16 that connects the tubular body 14 is connected to the tubular joint 12 in place of the tubular body 14.

  The receiving joint 16 has a spiral wave-equipped portion 61 having the same shape as that of the tubular body 14 on the proximal end side, and has a substantially cylindrical receiving portion 62 at the distal end of the helical wave-attached portion 61. A ring-shaped retaining member 63 is provided in the receiving portion 62 so that the retaining member 63 can be retained when the insertion joint 45 that holds one end of the tubular body 14 is inserted. The insertion joint 45 has an internal thread portion 45 a that is screwed into the tube body 14 on the inner peripheral surface on the side opposite to the insertion side in the longitudinal direction.

  Even in the connection structure 11 configured as described above, the receiving joint 16 is held by the pipe joint 12 and the bell mouth 13 without displacement so that the water stoppage is inhibited in the same manner as described above. Even if earth pressure is applied to the receiving joint 16 and the pipe joint 12, waterproofness can be secured.

In correspondence between the configuration of the present invention and the configuration of the one aspect,
The connection object of the present invention corresponds to the underground box 71,
Similarly,
The tube corresponds to the spiral grooved tube (tube) 14 or the receiving joint 16,
The coupling portion of the pipe joint corresponds to the female screw portion 21;
The connecting portion of the bell mouth corresponds to the male screw portion 31,
The present invention is not limited to the above configuration, and other forms can be adopted.

  For example, the protrusion 25 may be formed of a plurality of rod-like portions arranged in an annular shape, for example, instead of being cylindrical.

  Further, instead of the packing 15, a rubber sheet, sponge, nonwoven fabric, or the like can be used. It is also possible to make it water-swellable.

DESCRIPTION OF SYMBOLS 11 ... Tube connection structure 12 ... Pipe joint 13 ... Bell mouth 14 ... Pipe with spiral groove 16 ... Receptacle joint 21 ... Female thread part 23a ... Contact surface 25 ... Projection part 31 ... Male thread part 32a ... Contact surface 71 ... Underground Box 73 ... through hole

Claims (3)

A pipe joint that has a coupling portion that is coupled to the outer peripheral surface of the tubular body, and that has a contact surface that abuts around the through hole to be connected, and a coupling portion that is coupled to the inner peripheral surface of the tubular body, and a connection A bell mouth having an abutting surface that abuts the periphery of the target through-hole, sandwiching the periphery of the through-hole, and connecting the tubular body to the through-hole,
A tubular body connection structure comprising a protrusion that enters the through hole at a site on the inner peripheral side of the abutting surface of the pipe joint and on the outer peripheral side of the coupling portion. The tubular body connection structure according to claim 1, wherein the protrusion is cylindrical. It has a coupling part that is coupled to the outer peripheral surface of the tubular body, has a contact surface that abuts around the through hole to be connected, has a coupling part that couples to the inner peripheral surface of the tubular body, and penetrates the connection target In cooperation with a bell mouth having an abutting surface that abuts the periphery of the hole, a pipe joint that sandwiches the periphery of the through hole and connects the tubular body to the through hole,
A pipe joint provided with a protrusion that enters the through hole at a portion on the inner peripheral side of the contact surface and on the outer peripheral side of the coupling portion.

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