JP2018031412A - Pipe body connection structure and bell mouth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a sufficient water cut-off performance to be attained even though a connecting work is easy to perform.SOLUTION: Pipe body connecting structure 11 for use in connecting a pipe 12 with a spiral wave to a through-hole 22 using a bell mouth 51 is provided. The bell mouth 51 comprises an outer cylinder part 32, a pipe joint 31, an inner cylinder part 52 and an inner surface flange part 53. The outer cylinder part 32 has a female thread 34 threadedly engaging with the outer circumferential surface of the pipe 12 with the spiral wave and fitting onto the outer circumferential surface of the pipe 12 with the spiral wave. The pipe joint 31 comprises an outer surface flange part 33 having an abutment surface 35 expanding in an outer peripheral direction at one axial end of the outer cylinder part 32 and abutting on a periphery of the through-hole 22 being a connection object. The inner cylinder part 52 has a male thread 54 threadedly engaging with the inner circumferential surface of the pipe 12 with the spiral wave and inserted into the pipe 12 with the spiral wave. The inner surface flange part 53 has an abutment surface 55 expanding in an outer peripheral direction at one axial end of the inner cylinder part 52 and abutting on the periphery of the through-hole 22. An outside-pipe body water expansion part 36 expanding through absorption of moisture is formed in the inner circumferential surface of the outer cylinder part 32 of the pipe joint 31, an inside-pipe body water expansion part 56 expanding through absorption of moisture is formed in the outer circumferential surface of the inner cylinder part 52 of the bell mouth 51.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tube connection 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 specifically, sufficient water-stopping property can be obtained. It relates to such a tube connection structure.

  As a structure for connecting a tube with a spiral wave (FEP tube) as a tubular body to an underground box, there is one disclosed in Patent Document 1 below.

  In this structure, the tubular body is connected using a fastening member and a bell mouth with a flat flange. The fastening member is formed in a cylindrical shape, has a flange at one end in the longitudinal direction, and has an internal thread that is screwed onto the outer peripheral surface of the spiral wave tube on the inner peripheral surface of the cylindrical portion. An annular plate-like water-stopping layer made of sponge-like synthetic rubber is attached to the surface of the collar portion opposite to the cylindrical portion. The hole in the center of the water-stopping layer is set to be smaller than the thickness of the spiral wave tube, and the fastening member is fitted to the end of the spiral wave tube so that the end of the spiral wave tube protrudes from the collar Then, the water blocking layer will be greatly deformed.

  The flat flanged bell mouth is formed in a cylindrical shape, has a flange at one end in the longitudinal direction, and has an external thread that is threadedly engaged with the inner peripheral surface of the spiral wave tube on the outer peripheral surface of the cylindrical portion. . A packing is provided on the surface of the collar portion on the side having the cylindrical portion.

  In this configuration, connection is performed as follows. First, a fastening member is fitted into the end of the tube with a spiral wave and rotated by applying a force to deform the water blocking layer and project the end of the tube with the spiral wave. Next, the end of the spiral wave tube is inserted into the through hole of the underground box, and a flat mouth flanged bell mouth is screwed to the end of the spiral wave tube from the opposite side. Finally, by rotating the tightening member and tightening the periphery of the through hole with the tightening member and a bell mouth with a flat flange, water stoppage is achieved by the water stop layer, and connection without an adhesive can be performed.

  However, if the fastening member and the bell mouth with the flat flange are not formed accurately with respect to the dimensions of the pipe with the spiral wave to be connected, a strong fastening state cannot be obtained. Also, the work requires a force to deform the water blocking layer. Furthermore, there is a risk of damage to the waterstop layer that is pushed out while rotating at the end face of the tube. In addition, this waterstop layer is located only on a part of the outer peripheral surface of the tube, so there is sufficient stoppage. When excessive moisture enters between the fastening member and the spiral wave tube without water, the moisture easily enters between the spiral wave tube and the flat flange bell mouth. There is a fear.

  Although there is a connection structure (see Patent Document 2 below) that allows water to stop as a whole rather than a part of the outer peripheral surface of the tube body, the structure that attempts to stop water also on the inner peripheral surface of the tube body is this Not at all.

Japanese Patent No. 3090447 JP 2014-207752 A

  The main object of the present invention is to make it possible to obtain a sufficient water-stopping property while being easily connected.

  For this purpose, there are an outer cylinder part that has a female screw threadedly engaged with the outer peripheral surface of the tubular body on the inner peripheral surface, and projects in the outer peripheral direction at one axial end of the outer cylindrical part. A pipe joint provided with an outer surface flange having an abutting surface that abuts around the through-hole to be connected, and a male screw threadedly engaged with the inner peripheral surface of the pipe body are inserted into the pipe body. The tubular body is formed using a bell mouth including an inner cylindrical portion and an inner flange portion having an abutting surface projecting in an outer peripheral direction at one axial end of the inner cylindrical portion and abutting the periphery of the through hole. A tube connection structure for connecting to a through hole, wherein an outer tube water expansion portion that expands by absorption of moisture is formed on the inner peripheral surface of the outer tube portion of the pipe joint, and the inner tube portion of the bell mouth This is a tubular body connection structure in which a tubular water expansion portion that expands due to absorption of moisture is formed on the outer peripheral surface.

  In this configuration, the outer cylinder part of the pipe joint is fitted on the outer peripheral surface of the pipe body, the inner cylinder part of the bell mouth is fitted in the end part of the pipe body, and the outer surface collar part of the pipe joint and the inner surface collar part of the bell mouth are fitted. When the periphery of the through hole is sandwiched and buried in the ground, first, the water expansion portion outside the tube expands, loads the tube, and stops water between the tube joint and the tube. When a large amount of moisture enters, the water expansion part in the pipe expands and water is stopped between the pipe and the bell mouth while applying a load in a direction different from the load due to the expansion of the water expansion part outside the pipe, Moisture entering from between the pipe body and the pipe joint is prevented from entering the pipe body.

  According to the present invention, sufficient water stoppage can be obtained while the connection work is easy.

Sectional drawing of a pipe body connection structure. The side view of a tubular body connection structure. The one side sectional view of a pipe joint. The half sectional view of a bellmouth. Sectional drawing which shows the state before the water expansion of a pipe body connection structure. Explanatory drawing which shows how to attach a pipe with a spiral wave. Sectional drawing which shows an action state. The half sectional view which shows the decomposition | disassembly state of the tube connection structure 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.
The cross section of the principal part of the pipe body connection structure 11 is shown in FIG. The tube connection structure 11 is connected to the through hole 22 formed in the wall portion 21a of the underground box 21 such as a hand hole with the end of the tube 12 with a spiral wave as a tube being inserted, A pipe joint 31 and a bell mouth 51 are used. In particular, the pipe connection structure 11 can be easily connected by simply fitting the pipe joint 31 and the bell mouth 51 to the spiral wave pipe 12 without applying a large force.

  FIG. 2 is a side view of the pipe joint 31 and the bell mouth 51 in a state in which the pipe with spiral wave 12 is connected. As shown in this figure, the pipe joint 31 fits on the outer peripheral surface of the pipe with spiral wave 12 and bell mouth 51 is inserted into the end portion of the tube 12 with a spiral wave, and a portion of the pipe joint 31 and a portion of the bell mouth 51 sandwich the periphery of the through hole 22 in the thickness direction of the wall portion 21a. The connection status of is maintained.

  The spiral wave tube 12 is for protecting an electric wire (not shown) embedded in the ground and is made of synthetic resin. Spiral irregularities (spiral waves) are formed not only on the outer peripheral surface but also on the inner peripheral surface. The tube 12 with spiral waves is in a state of projecting vertically from the outer surface of the wall portion 21a of the underground box 21 in the connected state. The outer diameter and inner diameter of the spiral wave tube 12 and the pitch of the spiral wave vary depending on the manufacturer.

  The pipe joint 31 is made of synthetic resin and has a substantially cylindrical shape as shown in FIG. The pipe joint 31 includes an outer cylindrical portion 32 that fits on the outer peripheral surface of the spiral wave-attached tube 12 and an outer flange portion 33 that projects in the outer peripheral direction at one axial end of the outer cylindrical portion 32. An internal thread 34 is formed on the inner peripheral surface of the outer cylindrical portion 32 so as to be screwed into the outer peripheral surface of the spiral wave-equipped tube 72. The outer surface flange portion 33 is formed to have a larger diameter than the through hole 22 and has a contact surface 35 that contacts the periphery of the through hole 22 on the outer surface of the wall portion 21a.

  On the entire inner peripheral surface of the outer cylinder portion 32 including the female screw 34, a tubular body external water expansion portion 36 that expands by absorbing moisture is formed. The pipe outside water expansion part 36 is configured by attaching a sheet-like water stop material. 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. As the water expansion material, a powdery material, a sheet material, a liquid material, and the like can be used as appropriate. However, when a fiber material is used, the integrity with the fibers constituting the nonwoven fabric may be increased. Fixing the water stop material to the inner peripheral surface may be performed by integral molding when the pipe joint 31 is molded.

  A plurality of ribs 37 that are long along the axial direction are provided on the outer peripheral surface of the outer cylindrical portion 32 at intervals in the circumferential direction so that the rotation operation is easy.

  The contact surface 35 of the outer surface flange 33 is formed with a hole edge water expansion portion 38 that expands due to moisture absorption. For this reason, the contact surface 35 indirectly contacts the periphery of the through hole 22 via the hole edge water expansion portion 38. The hole edge water expansion part 38 is comprised with a sheet-like water stop material similarly to the above-mentioned pipe outside water expansion part 36. As shown in FIG.

  The hole edge water expansion portion 38 is formed on a raised portion 39 that increases the thickness of the outer surface flange portion 33. The raised portion 39 is formed of a soft rubber layer having an appropriate thickness. As the soft rubber layer, a low-hardness rubber that can be compressed and deformed by being pushed with a finger, for example, an altitude of 20 or less, more preferably a hardness of about 10 ° to 15 ° (JIS-A) can be suitably used. The soft rubber layer may be integrally formed when the pipe joint 31 is formed, but may be separately attached with an adhesive. The soft rubber layer is non-water-swellable, but may have water-swellability that expands by absorbing moisture.

  The bell mouth 51 is made of a synthetic resin, and as shown in FIG. 4, the inner cylinder portion 52 inserted into the spiral wave tube 12, and the inner flange portion projecting in the outer peripheral direction at one end in the axial direction of the inner cylinder portion 52. 53. A male screw 54 is formed on the outer peripheral surface of the inner cylinder portion 52 so as to be screwed into the inner peripheral surface of the spiral wave tube 12. The inner surface flange 53 is formed to have a diameter larger than that of the through hole 22, and has a contact surface 55 that contacts the periphery of the through hole 22 on the inner surface of the wall portion 21 a at the outer peripheral side portion.

  A tubular water expansion portion 56 that expands by absorbing moisture is formed on the entire outer peripheral surface of the inner cylinder portion 52 including the male screw 54. The tubular body water expansion part 56 is formed in the same manner as the above-mentioned tubular body water expansion part 36. A pipe end water expansion portion 57 that expands due to the absorption of moisture is formed on the inner peripheral side portion of the inner surface flange portion 53 facing the end portion of the spiral wave-attached tube 12 together with the pipe internal water expansion portion 56. The pipe body water expansion part 56 and the pipe end water expansion part 57 are integrally formed of the same water stop material.

  The contact surface 55 of the inner surface flange 53 is formed with a hole edge water expansion portion 58 that expands due to moisture absorption. For this reason, the contact surface 55 indirectly contacts the periphery of the through hole 22 via the hole edge water expansion portion 58. The hole edge water expansion part 58 is made of a sheet-like water-stopping material in the same manner as the above-mentioned pipe outside water expansion part 36 and the like.

  The hole edge water expansion portion 58 is formed on the raised portion 59 that increases the thickness of the inner surface flange portion 53. As in the case of the pipe joint 31, the raised portion 59 is formed of a soft rubber layer having an appropriate thickness. Accordingly, the surface of the pipe end water expansion portion 57 on the inner cylinder portion 52 side is set lower than the surface of the hole edge water expansion portion 58, and the pipe end water expansion portion 57 is provided around the pipe end water expansion portion 57. A state of forming a non-water-absorbing step portion that surrounds is formed.

  The dimensions of the pipe joint 31 and the bell mouth 51 and the thread (the female thread 34 and the male thread 54) having such a configuration are set as follows in relation to the spiral wave-attached pipe 12. That is, the inner diameter of the outer cylindrical portion 32 of the pipe joint 31 and the pitch and height of the female screw 34, and the outer diameter of the inner cylindrical portion 52 of the bell mouth 51 and the pitch and height of the male screw 54 are determined by the manufacturing company of the spiral wave tube 12. Set to absorb the dimensional difference of each. In particular, between the surface of the pipe external water expansion part 36 before expansion in the pipe joint 31 and the surface of the pipe with the spiral wave fitted with the pipe joint 31, the opposite of the outer flange part 33 in the axial direction of the pipe joint 31. A moisture passage 15 through which moisture passes is formed from the end on the side to the end on the outer flange 33 side (see FIG. 5). The mode of the moisture passage 15 is set in consideration of the performance of the extra-tubular water expansion section 36.

  In order to form the moisture passage 71 while absorbing the dimensional difference of the pipe 12 with the spiral wave and to simplify the screwing at the time of the connection work, the pitch number of the female thread 34 of the pipe joint 31 may be reduced. For example, as shown in FIG. 3, the pitch number of the internal thread 34 can be reduced to about one pitch. The male screw 54 of the bell mouth 51 may be set to a small number of pitches in order to simplify the screwing at the time of connection work. However, in order to ensure tensile resistance, the pitch number of the male screws 54 is larger than one pitch. As shown in FIG. 4, it is good to have about 2 pitches.

  In the pipe connection structure 11 constituted by the pipe joint 31 and the bell mouth 51 as described above, the spiral wave-attached pipe 12 is connected as follows. This connection is completed through an installation stage and a water absorption stage.

  The attachment stage includes the steps (a) to (d) shown in FIG. First, the pipe joint 31 is fitted to the end portion on the side to which the pipe 12 with the spiral wave is connected (FIG. 6A). When fitting, the end opposite to the outer flange 33 is directed toward the end of the spiral wave tube 12. Since the fitting has the moisture passage 15, the fitting can be easily performed by rotating with a light force. Next, the pipe 12 with the spiral wave with the pipe joint 31 fitted and the end exposed is fitted into the through hole 22 (FIG. 6B). Subsequently, the inner cylinder portion 52 of the bell mouth 51 is inserted into the end portion of the spiral wave-attached tube 12 that protrudes on the opposite side of the through hole 22, that is, on the inner surface side (FIG. 6C). The inner cylinder portion 52 is inserted while rotating the bell mouth 51 until the end portion of the spiral wave-attached tube 12 hits the tube end water expansion portion 57 of the inner surface flange portion 53 of the bell mouth 51. Since the water stop material constituting the pipe end water expansion portion 57 is made of nonwoven fabric, it maintains a certain form and is strong, so that even if the end portion of the spiral wave-attached tube 12 hits strongly, water expandability can be secured. . Finally, the inner flange 53 of the bell mouth 51 is applied to the periphery of the through hole 22 and rotated in the direction of tightening the pipe joint 31, so that the inner flange 53 of the bell mouth 51 and the outer flange 33 of the pipe joint 31 are The periphery of the through hole 22 is tightened inward and outward (see FIG. 5). As described above, the attachment work by the pipe joint 31 and the bell mouth 51 can be performed very easily without requiring a large force.

  When the underground box 21 is buried in the ground after such an attachment stage, the process proceeds to a water absorption stage that absorbs moisture in the soil. In the water absorption stage, first, as shown in FIG. 5, the moisture that enters the moisture passage 15 with respect to the water expansion portion 36 outside the tubular body having the moisture passage 15 between the pipe joint 31 and the spiral wave-attached tube 12. Acts to expand the outside-tube water expansion portion 36. The pipe outside water expansion part 36 expands as a whole as the moisture enters the moisture passage 15. By this expansion, the spiral wave tube 36 is compressed mainly from the outer peripheral direction, and the positional relationship with the pipe joint 31 is fixed.

  In synchronism with the expansion of the pipe outside water expansion part 36 in this way, the hole edge water expansion parts 38 and 58 of the pipe joint 31 and the bell mouth 51 are caused by the action of moisture in the soil because of their location and size. It quickly expands quickly and exerts a strong force for tightening the periphery of the through hole by the pipe joint 31 and the bell mouth 51, and performs water stop between the through hole 22 and the outside. Since the water stop material which comprises the hole edge water expansion parts 38 and 58 is comprised with the nonwoven fabric, this water stop maintains a fixed form and is strong, and also the back side of the hole edge water expansion parts 38 and 58 Since the raised portions 39 and 59 made of a soft rubber layer are provided, the soft rubber layer has a repulsive force while being compressed and deformed when the hole edge water expansion portions 38 and 58 are tightened. For this reason, it becomes a stronger and better water stop state.

  As shown in FIG. 7, the water that has expanded the pipe external water expansion section 36 travels back along the outer peripheral surface of the spiral wave-attached pipe 12, reaches the pipe end water expansion section 57, and reaches the pipe end water expansion section 57. The expansion part 57 and the tubular water expansion part 56 are expanded. Since the pipe end water expansion part 57 and the pipe internal water expansion part 56 are integrated, a series of expansions are performed extremely smoothly. Since the stepped portion including the raised portion 59 is formed around the pipe end water expansion portion 57, the moisture that enters is efficiently used for the expansion of the pipe end water expansion portion 57 and the tubular water expansion portion 56. Can do. The pipe end water expansion part 57 and the pipe internal water expansion part 56 are mainly inflated by the water that has expanded the pipe external water expansion part 36. For example, depending on the manner in which the bell mouth 51 is screwed, the bell mouth In some cases, the hole edge water expansion portion 51 may be expanded by the expanded water.

  By the expansion of the pipe end water expansion portion 57, the end of the spiral wave-equipped tube 12 is loaded mainly in the direction of the pipe joint 31 as shown by the phantom line in FIG. The spiral wave tube 12 is loaded in a direction extending from the inner peripheral side to the outer peripheral side, and the entire outer peripheral surface of the spiral wave tube 12 covered with the pipe joint 31 as shown in FIG. Water is stopped at the end of the spiral wave tube 12 and the inner peripheral surface of the portion where 51 is inserted.

  Thus, the connection state of the pipe 12 with the spiral wave to the through hole 22 of the underground box 21 is determined by the clamping between the pipe joint 31 and the bell mouth 51 and the expansion pressure of each of the water expansion portions 36, 38, 56, 57, 58. Strongly held. In addition, each of the water expansion portions 36, 38, 56, 57, 58 expands in different directions, and in particular, the pipe end water expansion portion 57 generates a force that presses the end of the spiral wave tube 12 toward the pipe joint 31. Compared with the case where the water is tightly attached to the spiral wave tube 12 only by expansion in one direction, water can be stopped at a high degree in each part, and as a result, sufficient water stoppage can be obtained.

  As for the water stop, in addition to the water stop on the outer peripheral side of the spiral wave-equipped tube 12 by the pipe external water expansion portion 36, the water stop on the inner peripheral side of the spiral wave-attached tube 12 by the pipe internal water expansion portion 56 is also performed. As a result, sufficient water stoppage can be obtained. In addition, since the moisture passage 15 is provided, water can be reliably stopped at the end of the spiral wave-attached tube 12 and the inner peripheral side.

Other examples will be described below. In this description, the same components as those described above are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 8 is a half sectional view showing a disassembled state of the tube connection structure 11 having a configuration in which the tube 12 with spiral wave is not directly connected to the through hole 22 but is connected via the receiving joint 71. The example which used the above-mentioned pipe joint 31 and the bell mouth 51 for the connection of the receiving joint 71 with respect to is shown. That is, the inheritance 71 corresponds to the tubular body of the present invention.

  The receiving joint 71 has a free end side portion 71 a that receives the insertion joint 72 fixed to the end of the spiral wave-attached tube 12, and the proximal end portion 71 b connected to the through hole 22 is the same as the spiral wave-attached tube 12. Since it is the same structure, the pipe joint 31 and the bell mouth 51 are comprised similarly to the above-mentioned.

  FIG. 9 is a cross-sectional view showing the tubular body connection structure 11 configured to maintain water-stopping performance even when earth pressure is applied. A through-hole is formed in a portion on the inner peripheral side of the outer surface flange portion 33 of the pipe joint 31. 22 is provided with a cylindrical projecting portion 75 that enters 22. An annular packing 76 that seals between the projecting portion 75 and the through hole 22 is provided on the outer peripheral side of the projecting portion 75. This tube connection structure 11 directly connects the tube 12 with a spiral wave to the through hole 22, and the tube joint 31 and the bell mouth 51 are configured in the same manner as described above.

In correspondence between the configuration of the present invention and the configuration of the above-described embodiment,
The tubular body of the present invention corresponds to the above-described spiral wave-equipped tube 12 and the receiving joint 71.
The present invention is not limited to the above-described configuration, and other configurations can be adopted.

DESCRIPTION OF SYMBOLS 11 ... Tube connection structure 12 ... Pipe with spiral wave 15 ... Moisture passage 22 ... Through-hole 31 ... Pipe joint 32 ... Outer cylinder part 33 ... Outer surface flange part 34 ... Female thread 35 ... Abutting surface 36 ... Tube outer water expansion part 51 ... Bellmouth 52 ... Inner cylinder part 53 ... Inner collar part 54 ... Male screw 55 ... Abutting surface 56 ... In-cylinder water expansion part 57 ... Pipe end water expansion part 58 ... Hole edge water expansion part 59 ... Uplift part 71 ... Receiver Fitting

  The present invention relates to a tube connection 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 specifically, sufficient water-stopping property can be obtained. It relates to such a tube connection structure.

  As a structure for connecting a tube with a spiral wave (FEP tube) as a tubular body to an underground box, there is one disclosed in Patent Document 1 below.

  In this structure, the tubular body is connected using a fastening member and a bell mouth with a flat flange. The fastening member is formed in a cylindrical shape, has a flange at one end in the longitudinal direction, and has an internal thread that is screwed onto the outer peripheral surface of the spiral wave tube on the inner peripheral surface of the cylindrical portion. An annular plate-like water-stopping layer made of sponge-like synthetic rubber is attached to the surface of the collar portion opposite to the cylindrical portion. The hole in the center of the water-stopping layer is set to be smaller than the thickness of the spiral wave tube, and the fastening member is fitted to the end of the spiral wave tube so that the end of the spiral wave tube protrudes from the collar Then, the water blocking layer will be greatly deformed.

  The flat flanged bell mouth is formed in a cylindrical shape, has a flange at one end in the longitudinal direction, and has an external thread that is threadedly engaged with the inner peripheral surface of the spiral wave tube on the outer peripheral surface of the cylindrical portion. . A packing is provided on the surface of the collar portion on the side having the cylindrical portion.

  In this configuration, connection is performed as follows. First, a fastening member is fitted into the end of the tube with a spiral wave and rotated by applying a force to deform the water blocking layer and project the end of the tube with the spiral wave. Next, the end of the spiral wave tube is inserted into the through hole of the underground box, and a flat mouth flanged bell mouth is screwed to the end of the spiral wave tube from the opposite side. Finally, by rotating the tightening member and tightening the periphery of the through hole with the tightening member and a bell mouth with a flat flange, water stoppage is achieved by the water stop layer, and connection without an adhesive can be performed.

  However, if the fastening member and the bell mouth with the flat flange are not formed accurately with respect to the dimensions of the pipe with the spiral wave to be connected, a strong fastening state cannot be obtained. Also, the work requires a force to deform the water blocking layer. Furthermore, there is a risk of damage to the waterstop layer that is pushed out while rotating at the end face of the tube. In addition, this waterstop layer is located only on a part of the outer peripheral surface of the tube, so there is sufficient stoppage. If excessive moisture enters between the fastening member and the spiral wave tube without water, the moisture easily enters between the spiral wave tube and the flat flange bell mouth. There is a fear.

  Although there is a connection structure (see Patent Document 2 below) that allows water to stop as a whole rather than a part of the outer peripheral surface of the tube body, the structure that attempts to stop water also on the inner peripheral surface of the tube body is this Not at all.

Japanese Patent No. 3090447 JP 2014-207752 A

  The main object of the present invention is to make it possible to obtain a sufficient water-stopping property while being easily connected.

For this purpose, there are an outer cylinder part that has a female screw threadedly engaged with the outer peripheral surface of the tubular body on the inner peripheral surface, and projects in the outer peripheral direction at one axial end of the outer cylindrical part. A pipe joint provided with an outer surface flange having an abutting surface that abuts around the through-hole to be connected, and a male screw threadedly engaged with the inner peripheral surface of the pipe body are inserted into the pipe body. The tubular body is formed using a bell mouth including an inner cylindrical portion and an inner flange portion having an abutting surface projecting in an outer peripheral direction at one axial end of the inner cylindrical portion and abutting the periphery of the through hole. a tube connection structure for connecting the through hole, the inner peripheral surface of the outer tube portion of the pipe joint, a sheet-like tube outside water swelling portion consisting of water stopping material is the inner peripheral surface expands by absorption of moisture is formed along the the outer peripheral surface of the inner cylindrical portion of the bell mouth, it expands by absorption of water Sea Tube body water expansion unit consisting Jo water stopping material is a tube connection structure formed along the outer peripheral surface.

  In this configuration, the outer cylinder part of the pipe joint is fitted on the outer peripheral surface of the pipe body, the inner cylinder part of the bell mouth is fitted in the end part of the pipe body, and the outer surface collar part of the pipe joint and the inner surface collar part of the bell mouth are fitted. When the periphery of the through hole is sandwiched and buried in the ground, first, the water expansion portion outside the tube expands, loads the tube, and stops water between the tube joint and the tube. When a large amount of moisture enters, the water expansion part in the pipe expands and water is stopped between the pipe and the bell mouth while applying a load in a direction different from the load due to the expansion of the water expansion part outside the pipe, Moisture entering from between the pipe body and the pipe joint is prevented from entering the pipe body.

  According to the present invention, sufficient water stoppage can be obtained while the connection work is easy.

Sectional drawing of a pipe body connection structure. The side view of a tubular body connection structure. The one side sectional view of a pipe joint. The half sectional view of a bellmouth. Sectional drawing which shows the state before the water expansion of a pipe body connection structure. Explanatory drawing which shows how to attach a pipe with a spiral wave. Sectional drawing which shows an action state. The half sectional view which shows the decomposition | disassembly state of the tube connection structure 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.
The cross section of the principal part of the pipe body connection structure 11 is shown in FIG. The tube connection structure 11 is connected to the through hole 22 formed in the wall portion 21a of the underground box 21 such as a hand hole with the end of the tube 12 with a spiral wave as a tube being inserted, A pipe joint 31 and a bell mouth 51 are used. In particular, the pipe connection structure 11 can be easily connected by simply fitting the pipe joint 31 and the bell mouth 51 to the spiral wave pipe 12 without applying a large force.

  FIG. 2 is a side view of the pipe joint 31 and the bell mouth 51 in a state in which the pipe with spiral wave 12 is connected. As shown in this figure, the pipe joint 31 fits on the outer peripheral surface of the pipe with spiral wave 12 and bell mouth 51 is inserted into the end portion of the tube 12 with a spiral wave, and a portion of the pipe joint 31 and a portion of the bell mouth 51 sandwich the periphery of the through hole 22 in the thickness direction of the wall portion 21a. The connection status of is maintained.

  The spiral wave tube 12 is for protecting an electric wire (not shown) embedded in the ground and is made of synthetic resin. Spiral irregularities (spiral waves) are formed not only on the outer peripheral surface but also on the inner peripheral surface. The tube 12 with spiral waves is in a state of projecting vertically from the outer surface of the wall portion 21a of the underground box 21 in the connected state. The outer diameter and inner diameter of the spiral wave tube 12 and the pitch of the spiral wave vary depending on the manufacturer.

The pipe joint 31 is made of synthetic resin and has a substantially cylindrical shape as shown in FIG. The pipe joint 31 includes an outer cylindrical portion 32 that fits on the outer peripheral surface of the spiral wave-attached tube 12 and an outer flange portion 33 that projects in the outer peripheral direction at one axial end of the outer cylindrical portion 32. An internal thread 34 is formed on the inner peripheral surface of the outer cylindrical portion 32 so as to be screwed onto the outer peripheral surface of the spiral wave tube 12 . The outer surface flange portion 33 is formed to have a larger diameter than the through hole 22 and has a contact surface 35 that contacts the periphery of the through hole 22 on the outer surface of the wall portion 21a.

  On the entire inner peripheral surface of the outer cylinder portion 32 including the female screw 34, a tubular body external water expansion portion 36 that expands by absorbing moisture is formed. The pipe outside water expansion part 36 is configured by attaching a sheet-like water stop material. 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. As the water expansion material, a powdery material, a sheet material, a liquid material, and the like can be used as appropriate. However, when a fiber material is used, the integrity with the fibers constituting the nonwoven fabric may be increased. Fixing the water stop material to the inner peripheral surface may be performed by integral molding when the pipe joint 31 is molded.

  A plurality of ribs 37 that are long along the axial direction are provided on the outer peripheral surface of the outer cylindrical portion 32 at intervals in the circumferential direction so that the rotation operation is easy.

  The contact surface 35 of the outer surface flange 33 is formed with a hole edge water expansion portion 38 that expands due to moisture absorption. For this reason, the contact surface 35 indirectly contacts the periphery of the through hole 22 via the hole edge water expansion portion 38. The hole edge water expansion part 38 is comprised with a sheet-like water stop material similarly to the above-mentioned pipe outside water expansion part 36. As shown in FIG.

  The hole edge water expansion portion 38 is formed on a raised portion 39 that increases the thickness of the outer surface flange portion 33. The raised portion 39 is formed of a soft rubber layer having an appropriate thickness. As the soft rubber layer, a low-hardness rubber that can be compressed and deformed by being pushed with a finger, for example, an altitude of 20 or less, more preferably a hardness of about 10 ° to 15 ° (JIS-A) can be suitably used. The soft rubber layer may be integrally formed when the pipe joint 31 is formed, but may be separately attached with an adhesive. The soft rubber layer is non-water-swellable, but may have water-swellability that expands by absorbing moisture.

  The bell mouth 51 is made of a synthetic resin, and as shown in FIG. 4, the inner cylinder portion 52 inserted into the spiral wave tube 12, and the inner flange portion projecting in the outer peripheral direction at one end in the axial direction of the inner cylinder portion 52. 53. A male screw 54 is formed on the outer peripheral surface of the inner cylinder portion 52 so as to be screwed into the inner peripheral surface of the spiral wave tube 12. The inner surface flange 53 is formed to have a diameter larger than that of the through hole 22, and has a contact surface 55 that contacts the periphery of the through hole 22 on the inner surface of the wall portion 21 a at the outer peripheral side portion.

  A tubular water expansion portion 56 that expands by absorbing moisture is formed on the entire outer peripheral surface of the inner cylinder portion 52 including the male screw 54. The tubular body water expansion part 56 is formed in the same manner as the above-mentioned tubular body water expansion part 36. A pipe end water expansion portion 57 that expands due to the absorption of moisture is formed on the inner peripheral side portion of the inner surface flange portion 53 facing the end portion of the spiral wave-attached tube 12 together with the pipe internal water expansion portion 56. The pipe body water expansion part 56 and the pipe end water expansion part 57 are integrally formed of the same water stop material.

  The contact surface 55 of the inner surface flange 53 is formed with a hole edge water expansion portion 58 that expands due to moisture absorption. For this reason, the contact surface 55 indirectly contacts the periphery of the through hole 22 via the hole edge water expansion portion 58. The hole edge water expansion part 58 is made of a sheet-like water-stopping material in the same manner as the above-mentioned pipe outside water expansion part 36 and the like.

  The hole edge water expansion portion 58 is formed on the raised portion 59 that increases the thickness of the inner surface flange portion 53. As in the case of the pipe joint 31, the raised portion 59 is formed of a soft rubber layer having an appropriate thickness. Accordingly, the surface of the pipe end water expansion portion 57 on the inner cylinder portion 52 side is set lower than the surface of the hole edge water expansion portion 58, and the pipe end water expansion portion 57 is provided around the pipe end water expansion portion 57. A state of forming a non-water-absorbing step portion that surrounds is formed.

The dimensions of the pipe joint 31 and the bell mouth 51 and the thread (the female thread 34 and the male thread 54) having such a configuration are set as follows in relation to the spiral wave-attached pipe 12. That is, the inner diameter of the outer cylindrical portion 32 of the pipe joint 31 and the pitch and height of the female screw 34, and the outer diameter of the inner cylindrical portion 52 of the bell mouth 51 and the pitch and height of the male screw 54 are determined by the manufacturing company of the spiral wave tube 12. Set to absorb the dimensional difference of each. In particular, between the surface of the pipe external water expansion portion 36 before expansion in the pipe joint 31 and the surface of the pipe 12 with the helical wave fitted with the pipe joint 31, the outer surface flange portion 33 in the axial direction of the pipe joint 31. A moisture passage 15 through which moisture passes from the opposite end to the outer flange 33 side end is formed (see FIG. 5). The mode of the moisture passage 15 is set in consideration of the performance of the extra-tubular water expansion section 36.

In order to form the moisture passage 15 while absorbing the dimensional difference of the pipe 12 with the spiral wave and to simplify the screwing at the time of the connection work, the pitch number of the female thread 34 of the pipe joint 31 may be reduced. For example, as shown in FIG. 3, the pitch number of the internal thread 34 can be reduced to about one pitch. The male screw 54 of the bell mouth 51 may be set to a small number of pitches in order to simplify the screwing at the time of connection work. However, in order to ensure tensile resistance, the pitch number of the male screws 54 is larger than one pitch. As shown in FIG. 4, it is good to have about 2 pitches.

  In the pipe connection structure 11 constituted by the pipe joint 31 and the bell mouth 51 as described above, the spiral wave-attached pipe 12 is connected as follows. This connection is completed through an installation stage and a water absorption stage.

  The attachment stage includes the steps (a) to (d) shown in FIG. First, the pipe joint 31 is fitted to the end portion on the side to which the pipe 12 with the spiral wave is connected (FIG. 6A). When fitting, the end opposite to the outer flange 33 is directed toward the end of the spiral wave tube 12. Since the fitting has the moisture passage 15, the fitting can be easily performed by rotating with a light force. Next, the pipe 12 with the spiral wave with the pipe joint 31 fitted and the end exposed is fitted into the through hole 22 (FIG. 6B). Subsequently, the inner cylinder portion 52 of the bell mouth 51 is inserted into the end portion of the spiral wave-attached tube 12 that protrudes on the opposite side of the through hole 22, that is, on the inner surface side (FIG. 6C). The inner cylinder portion 52 is inserted while rotating the bell mouth 51 until the end portion of the spiral wave-attached tube 12 hits the tube end water expansion portion 57 of the inner surface flange portion 53 of the bell mouth 51. Since the water stop material constituting the pipe end water expansion portion 57 is made of nonwoven fabric, it maintains a certain form and is strong, so that even if the end portion of the spiral wave-attached tube 12 hits strongly, water expandability can be secured. . Finally, the inner flange 53 of the bell mouth 51 is applied to the periphery of the through hole 22 and rotated in the direction of tightening the pipe joint 31, so that the inner flange 53 of the bell mouth 51 and the outer flange 33 of the pipe joint 31 are The periphery of the through hole 22 is tightened inward and outward (see FIG. 5). As described above, the attachment work by the pipe joint 31 and the bell mouth 51 can be performed very easily without requiring a large force.

When the underground box 21 is buried in the ground after such an attachment stage, the process proceeds to a water absorption stage that absorbs moisture in the soil. In the water absorption stage, first, as shown in FIG. 5, the moisture that enters the moisture passage 15 with respect to the water expansion portion 36 outside the tubular body having the moisture passage 15 between the pipe joint 31 and the spiral wave-attached tube 12. Acts to expand the outside-tube water expansion portion 36. The pipe outside water expansion part 36 expands as a whole as the moisture enters the moisture passage 15. By this expansion, the spiral wave tube 12 is compressed mainly from the outer peripheral direction, and the positional relationship with the pipe joint 31 is fixed.

In synchronism with the expansion of the pipe outside water expansion part 36 in this way, the hole edge water expansion parts 38 and 58 of the pipe joint 31 and the bell mouth 51 are caused by the action of moisture in the soil because of their location and size. It quickly expands quickly and exerts a strong force for tightening the periphery of the through hole 22 by the pipe joint 31 and the bell mouth 51, and performs water stop between the through hole 22 and the outside. Since the water stop material which comprises the hole edge water expansion parts 38 and 58 is comprised with the nonwoven fabric, this water stop maintains a fixed form and is strong, and also the back side of the hole edge water expansion parts 38 and 58 Since the raised portions 39 and 59 made of a soft rubber layer are provided, the soft rubber layer has a repulsive force while being compressed and deformed when the hole edge water expansion portions 38 and 58 are tightened. For this reason, it becomes a stronger and better water stop state.

  As shown in FIG. 7, the water that has expanded the pipe external water expansion section 36 travels back along the outer peripheral surface of the spiral wave-attached pipe 12, reaches the pipe end water expansion section 57, and reaches the pipe end water expansion section 57. The expansion part 57 and the tubular water expansion part 56 are expanded. Since the pipe end water expansion part 57 and the pipe internal water expansion part 56 are integrated, a series of expansions are performed extremely smoothly. Since the stepped portion including the raised portion 59 is formed around the pipe end water expansion portion 57, the moisture that enters is efficiently used for the expansion of the pipe end water expansion portion 57 and the tubular water expansion portion 56. Can do. The pipe end water expansion part 57 and the pipe internal water expansion part 56 are mainly inflated by the water that has expanded the pipe external water expansion part 36. For example, depending on the manner in which the bell mouth 51 is screwed, the bell mouth In some cases, the hole edge water expansion portion 51 may be expanded by the expanded water.

  By the expansion of the pipe end water expansion portion 57, the end of the spiral wave-equipped tube 12 is loaded mainly in the direction of the pipe joint 31 as shown by the phantom line in FIG. The spiral wave tube 12 is loaded in a direction extending from the inner peripheral side to the outer peripheral side, and the entire outer peripheral surface of the spiral wave tube 12 covered with the pipe joint 31 as shown in FIG. Water is stopped at the end of the spiral wave tube 12 and the inner peripheral surface of the portion where 51 is inserted.

  Thus, the connection state of the pipe 12 with the spiral wave to the through hole 22 of the underground box 21 is determined by the clamping between the pipe joint 31 and the bell mouth 51 and the expansion pressure of each of the water expansion portions 36, 38, 56, 57, 58. Strongly held. In addition, each of the water expansion portions 36, 38, 56, 57, 58 expands in different directions, and in particular, the pipe end water expansion portion 57 generates a force that presses the end of the spiral wave tube 12 toward the pipe joint 31. Compared with the case where the water is tightly attached to the spiral wave tube 12 only by expansion in one direction, water can be stopped at a high degree in each part, and as a result, sufficient water stoppage can be obtained.

  As for the water stop, in addition to the water stop on the outer peripheral side of the spiral wave-equipped tube 12 by the pipe external water expansion portion 36, the water stop on the inner peripheral side of the spiral wave-attached tube 12 by the pipe internal water expansion portion 56 is also performed. As a result, sufficient water stoppage can be obtained. In addition, since the moisture passage 15 is provided, water can be reliably stopped at the end of the spiral wave-attached tube 12 and the inner peripheral side.

Other examples will be described below. In this description, the same components as those described above are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 8 is a half sectional view showing a disassembled state of the tube connection structure 11 having a configuration in which the tube 12 with spiral wave is not directly connected to the through hole 22 but is connected via the receiving joint 71. The example which used the above-mentioned pipe joint 31 and the bell mouth 51 for the connection of the receiving joint 71 with respect to is shown. In other words, it is receiving joint hands 71 corresponds to the tube of the present invention.

  The receiving joint 71 has a free end side portion 71 a that receives the insertion joint 72 fixed to the end of the spiral wave-attached tube 12, and the proximal end portion 71 b connected to the through hole 22 is the same as the spiral wave-attached tube 12. Since it is the same structure, the pipe joint 31 and the bell mouth 51 are comprised similarly to the above-mentioned.

  FIG. 9 is a cross-sectional view showing the tubular body connection structure 11 configured to maintain water-stopping performance even when earth pressure is applied. A through-hole is formed in a portion on the inner peripheral side of the outer surface flange portion 33 of the pipe joint 31. 22 is provided with a cylindrical projecting portion 75 that enters 22. An annular packing 76 that seals between the projecting portion 75 and the through hole 22 is provided on the outer peripheral side of the projecting portion 75. This tube connection structure 11 directly connects the tube 12 with a spiral wave to the through hole 22, and the tube joint 31 and the bell mouth 51 are configured in the same manner as described above.

In correspondence between the configuration of the present invention and the configuration of the above-described embodiment,
The tubular body of the present invention corresponds to the above-described spiral wave-equipped tube 12 and the receiving joint 71.
The present invention is not limited to the above-described configuration, and other configurations can be adopted.

DESCRIPTION OF SYMBOLS 11 ... Tube connection structure 12 ... Pipe with spiral wave 15 ... Moisture passage 22 ... Through-hole 31 ... Pipe joint 32 ... Outer cylinder part 33 ... Outer surface flange part 34 ... Female thread 35 ... Abutting surface 36 ... Tube outer water expansion part 51 ... Bellmouth 52 ... Inner cylinder part 53 ... Inner collar part 54 ... Male screw 55 ... Abutting surface 56 ... In-cylinder water expansion part 57 ... Pipe end water expansion part 58 ... Hole edge water expansion part 59 ... Uplift part 71 ... Receiver Fitting

Claims (9)

An outer cylinder part that has a female screw threadedly engaged with the outer peripheral surface of the tubular body on the inner peripheral surface, and a penetration that projects in the outer peripheral direction at one end in the axial direction of the outer cylindrical part and is a connection target A pipe joint having an outer surface flange portion having an abutting surface that abuts the periphery of the hole, and an inner cylinder portion having an external thread on the outer peripheral surface to be screwed into the inner peripheral surface of the pipe body and inserted into the pipe body The tubular body is connected to the through-hole using a bell mouth provided with an inner flange that has an abutment surface that protrudes in the outer peripheral direction at one end in the axial direction of the inner cylindrical portion and abuts the periphery of the through-hole. A tube connection structure,
On the inner peripheral surface of the outer tube portion of the pipe joint, a tube outer water expansion portion that expands due to moisture absorption is formed,
A tubular body connection structure in which a tubular water expansion portion that expands by absorbing moisture is formed on the outer peripheral surface of the inner cylinder portion of the bell mouth. The tube body connection structure according to claim 1, wherein a tube end water expansion portion that expands due to moisture absorption is formed at an inner peripheral side portion of the inner surface flange portion where an end portion of the tube body is opposed. Between the surface of the pipe external water expansion portion before expansion in the pipe joint and the surface of the pipe body fitted with the pipe joint, from the opposite end of the outer surface flange portion in the axial direction of the pipe joint The tubular body connection structure according to claim 1 or 2, further comprising a moisture passage through which moisture passes to an end on the outer surface flange side. An inner cylinder portion that has an external thread on the outer peripheral surface that is threadedly engaged with the inner peripheral surface of the tube body, and a through-hole that projects in the outer peripheral direction at one end in the axial direction of the inner cylinder portion and is to be connected A bell mouth provided with an inner flange having an abutting surface that abuts on the periphery of
A bell mouth in which a tubular water expansion portion that expands by absorbing moisture is formed on the outer peripheral surface of the inner cylinder portion. The bell mouth of Claim 4 in which the pipe end water expansion | swelling part which expand | swells by absorption of a water | moisture content was formed in the inner peripheral side site | part which the edge part of the said tubular body opposes in the said inner surface collar part. The bell mouth according to claim 5, wherein the pipe body water expansion portion and the pipe end water expansion portion are integrated. The bell mouth as described in any one of Claims 4-6 in which the hole edge water expansion part which expand | swells by absorption of a water | moisture content was formed in the said contact surface. The hole edge water expansion portion is formed on a raised portion that increases the thickness of the inner surface flange,
The bell mouth according to claim 7, wherein a surface of the pipe end water expansion portion on the inner tube portion side is set lower than a surface of the hole edge water expansion portion. An outer cylinder part that has a female screw threadedly engaged with the outer peripheral surface of the tubular body on the inner peripheral surface, and a penetration that projects in the outer peripheral direction at one end in the axial direction of the outer cylindrical part and is a connection target A pipe joint having an outer surface flange portion having an abutting surface that abuts the periphery of the hole, and an inner cylinder portion having an external thread on the outer peripheral surface to be screwed into the inner peripheral surface of the pipe body and inserted into the pipe body The tubular body is connected to the through-hole using a bell mouth provided with an inner flange that has an abutment surface that protrudes in the outer peripheral direction at one end in the axial direction of the inner cylindrical portion and abuts the periphery of the through-hole. A tube connection method,
Of the water expansion parts that are formed on the inner peripheral surface of the outer cylinder part of the pipe joint and the outer peripheral surface of the inner cylinder part of the bell mouth and expand by absorption of moisture, the inner peripheral surface of the outer cylinder part of the pipe joint A tubular body connecting method for expanding the tubular water expansion portion on the outer peripheral surface of the inner cylinder portion of the bell mouth after the tubular tubular water expansion portion is expanded.

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