JP2012130192A - Inner tube, method of passing inner tube into external piping, and piping structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner tube that can be efficiently housed in an outer tube and can resist earth pressure.SOLUTION: An inner tube 1 is a flexible resin tube body. The inner tube 1 has crest portions 3 and trough portions 5 formed axially repeatedly on an outer circumferential region. The crest portions 3 and the trough portions 5 are formed independently in the axial direction of the inner tube 1. The crest portions 3 have an end width narrower than a bottom width of the trough portions 5. Since the crest portions 3 have a height (height relative to the trough portions 5) the same as a depth (depth relative to the crest portions 3) of the trough portions 5, the shape of the crest portions 3 can fit in the shape of the trough portions 5. Specifically, when adjacent inner tubes 1 are juxtaposed with the respective crest portions 3 and trough portions 5 positioned to each other, the crest portions 3 and the trough portions 5 engage with each other. The end (outer circumferential surface) of the crest portions 3 is thus in contact with the bottom (outer circumferential surface) of the trough portions 5.

Description

  The present invention relates to an inner pipe capable of inserting a plurality of inner pipes into one outer pipe (external pipe) and dividing the pipe, a method for inserting the inner pipe into the external pipe, and a pipe structure. is there.

  Conventionally, when a cable is buried and laid in the ground, a plurality of inner pipes are laid in one external pipe, and the inner pipe can be divided to branch the pipe. .

  A plurality of such inner pipes are arranged inside an external pipe line material buried in the ground through a hand hole or the like, and a resin corrugated pipe may be used to give flexibility ( For example, Patent Document 1).

JP 2000-134780 A

  However, when a corrugated pipe is used as the inner pipe, when the inner pipe is inserted into the external pipe, if the corrugations between the inner pipes are caught, it is difficult to wire the inner pipe. The crest width of the corrugated portion is set larger than the trough width so that the corrugations of the corrugated tubes are not caught.

  On the other hand, in order to increase the storage efficiency of the inner pipe with respect to the external pipe, it is necessary to store a larger number of inner pipes with respect to the external pipe of the same size. However, the insertion interval between the inner tubes in the cross section cannot be less than or equal to the outer diameter of the inner tube, and there is a limit.

  In addition, the external pipe is usually buried and used in the ground, but since the earth pressure is not applied to the inner pipe that is inserted inside, if the external pipe is corroded or damaged, the inner pipe May be flattened and the internal cable may not be sufficiently protected. However, the use of a higher strength inner tube may lead to an increase in cost and a decrease in the storage efficiency described above.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide an inner pipe or the like that can be accommodated with high efficiency inside an external pipe, and that can also counteract earth pressure. .

  In order to achieve the above-mentioned object, the first invention is an inner tube that is inserted into an external pipe and used, and is a resin corrugated pipe in which crests and troughs are alternately formed on the outer periphery. The width of the crest is smaller than the width of the trough, and when a plurality of inner pipes are adjacent to each other, each crest and trough of the adjacent inner pipes mesh with each other, The inner tube is characterized in that the tip of the crest can contact the bottom of the valley of the other inner tube.

  In the cross section in the axial direction, a flat portion is formed at each of the end portion of the peak portion and the bottom portion of the valley portion, and the width of the flat portion of the peak portion is smaller than the width of the flat portion of the valley portion. Is desirable.

  A concave portion is formed at the end portion of the peak portion, and a convex portion is formed at the bottom portion of the valley portion, and the convex portion is formed when the peak portion and the valley portion of adjacent inner pipes are engaged with each other. It may be possible to fit into the recess.

  According to 1st invention, since the crest and trough of the outer periphery of adjacent inner pipes can mutually mesh, compared with the case where the outer peripheries in the crests of a plurality of inner pipes contact each other. It is possible to reduce the distance between the inner tubes by the height of the mountain valley. Therefore, it is possible to increase the number of inner pipes that can be inserted into an external pipe having a predetermined inner diameter. That is, the installation density of the inner pipe can be increased.

  Moreover, since the edge part of a peak part and the bottom part of a trough part contact, it is possible to increase the contact area of inner pipes. For this reason, in a state where a plurality of tubes are inserted into the outer tube, even if force is applied in the direction in which the outer tube is crushed, stress concentration between the tubes hardly occurs, and the compressive strength of the entire inner tube in the laid state can be increased. it can. Moreover, even if the height of the peak portion is increased, the valleys mesh with each other, so that a useless space in the cross section is reduced. Therefore, it is possible to save space while increasing the height of the mountain portion to ensure high strength against earth pressure.

  In particular, if a flat part is formed at the end part of the peak part and the bottom part of the valley part, when the peak part and the valley part are engaged, the flat parts can be reliably brought into contact with each other. The pressure receiving area can be increased with respect to compression in the radial direction.

  Moreover, by forming the recesses and the projections in the peaks and valleys, the compressive strength can be further increased without increasing the outer diameter of the inner tube.

  The second invention is a method of inserting an inner pipe into an external pipe, wherein the inner pipe is a resin corrugated pipe in which crests and troughs are alternately formed on the outer periphery, The width of the part is smaller than the width of the valley part, a plurality of inner pipes are adjacent to each other, and the tip of the peak part of one inner pipe is brought into contact with the bottom part of the valley part of the other inner pipe, thereby The crests and troughs of the matching inner pipes are meshed with each other, a plurality of meshed inner pipe bundles are bundled together, and the bundled inner pipe bundles are inserted into the external pipe. This is an inner tube insertion method.

  3rd invention is a piping structure, Comprising: It embed | buried external piping and the some inner pipe penetrated by the said external piping, The said inner pipe has a peak part and trough part in the outer peripheral part. Is a resin corrugated tube formed alternately, the width of the crest is smaller than the width of the trough, and in the adjacent inner pipe, the tip of the crest of one inner pipe is the other The piping structure is characterized in that the respective crests and troughs of the adjacent inner pipes mesh with each other by contacting the bottom of the trough part of the inner pipe. In addition to the plurality of first inner pipes, a second inner pipe, which is a corrugated pipe having a diameter different from that of the first inner pipe, is inserted into the external pipe, and the width of the peak portion of the first inner pipe is increased. The width of the valley of the second inner pipe is smaller than the width of the valley of the second inner pipe, and the width of the valley of the first inner pipe is smaller than the width of the first inner pipe. The pitch of the peaks and valleys of the second inner pipe and the pitch of the peaks and valleys of the second inner pipe may be substantially the same, and the peaks and valleys of the adjacent first inner pipe and second inner pipe may be engaged with each other. .

  According to the 2nd and 3rd invention, the installation density of an inner pipe is high and the piping structure which is excellent in compressive strength can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the inner pipe | tube etc. which can be accommodated in the inside of external piping with high efficiency, and can also counter against earth pressure can be provided.

The figure which shows the inner pipe | tube 1. FIG. It is a figure which shows the inner pipe | tube 1, (a) is an axial sectional view, (b) is the A section enlarged view of (a). The figure which shows the state which meshes inner pipes 1 mutually. The figure which shows the state which penetrated the some inner pipe | tube 1 to the external piping 7. FIG. It is sectional drawing which shows the state which penetrated the some inner pipe to the external piping 7, (a) is a figure which shows the case where the conventional inner pipe 1a is used, (b) is the case where the inner pipe 1 of this invention is used FIG. The figure which shows the inner pipe | tube 10. FIG. It is a figure which shows the inner pipe | tube 10, (a) is an axial sectional view, (b) is a figure which shows the state which meshes inner pipes 10 mutually. The figure which shows the other shape of the peak part 3 and the trough part 5. FIG. Sectional drawing which shows the state which penetrated the some inner pipe | tube to the external piping 7. FIG.

  Hereinafter, an inner pipe 1 according to an embodiment of the present invention will be described. FIG. 1 is a view showing an inner pipe 1. The inner tube 1 is a flexible resin tube. The inner pipe 1 has a crest 3 and a trough 5 repeatedly formed in the axial direction on the outer periphery. As the inner pipe 1, for example, a polyethylene pipe can be used.

  Fig.2 (a) is an axial cross section of the inner pipe | tube 1, FIG.2 (b) is the A section enlarged view of Fig.2 (a). As shown in FIG. 2A, the crest 3 and the trough 5 are formed independently in the axial direction of the inner tube 1.

  The crest 3 and the trough 5 have a substantially rectangular cross section, and are located at the end of the crest 5 (the outermost part on the outer peripheral surface of the crest 5) and the bottom of the trough 5 (the innermost part on the outer peripheral surface of the trough 3). , Flat portions are formed respectively. In addition, a taper is slightly formed in the wall part which connects the edge part of the peak part 3, and the bottom part of the trough part 5. FIG.

  As shown in FIG. 2B, the width (B in the drawing) of the peak portion 3 (the end portion thereof) is narrower than the width (C in the drawing) of the valley portion 5 (the bottom portion thereof). Since the height of the crest 3 (height with respect to the trough 5) is the same as the depth of the trough 5 (depth with respect to the crest 3), the shape of the crest 3 fits into the shape of the trough 5. It is possible.

  FIG. 3A is a diagram showing a state in which the inner pipes 1 are adjacent to each other. First, the positions of the mountain portions 3 and the valley portions 5 of the adjacent inner pipes 1 are adjacent to each other. In this state, as shown in FIG. 3B, when the inner pipes are brought into contact with each other, the crest 3 and the trough 5 are engaged with each other. That is, the end portion (outer peripheral surface) of the peak portion 3 is in contact with the bottom portion (outer peripheral surface) of the valley portion 5.

  Note that when the crests 3 and the troughs 5 of the inner pipes 1 are engaged with each other, it is desirable that a slight gap is formed between the walls of the crests 3 and the troughs 5. This is to ensure flexibility even when the inner tubes 1 are engaged with each other.

  FIG. 4 is a view showing a state in which a plurality of inner pipes 1 are inserted into the external pipe 7. As the external pipe 7, a metal pipe, a flexible resin pipe having a wavy shape (not shown), or the like can be used.

  The operation of inserting the inner pipe 1 into the external pipe 7 is performed as follows. First, a plurality of inner pipes 1 are bundled so that their crests and troughs mesh with each other as described above. In this state, the bundled inner pipes 1 are held by a band, a string, or the like that is not shown. That is, the band etc. are arrange | positioned and hold | maintained by the predetermined interval of an axial direction including the both ends of the bundled inner pipe | tube 1.

  The plurality of inner pipes 1 held in a bundle are inserted into the external pipe 7. The inner pipe 1 may be inserted after the external pipe 7 is laid in advance, or a plurality of inner pipes 1 may be laid after being inserted into the external pipe 7.

  FIG. 5 is a conceptual diagram of a cross section in a state where a plurality of inner pipes are inserted into an external pipe. In the conventional inner pipe 1 a, the width of the end portion of the peak portion 3 is larger than the width of the bottom portion of the valley portion 5. Usually, the shape of the corrugated tube is designed so that the width of the end portion of the outer peripheral surface of the peak portion 3 and the width of the end portion of the inner peripheral surface of the valley portion 5 are substantially the same from the viewpoint of flexibility and manufacturability Is done. Therefore, the width of the outer peripheral surface of the valley portion 5 is narrower by the thickness than the width of the end portion of the peak portion 3. By doing in this way, the peak part 3 and the trough part 5 do not mesh, but it is excellent in workability | operativity also when laying adjacently. For example, in the inner diameter φ24, the outer diameter of the peak is 32 mm and the outer diameter of the valley is 26 mm. In the inner diameter φ36, the outer diameter of the crest is 43 mm and the outer diameter of the trough is about 38 mm. When piping as shown in FIG. 5, the outer diameter of the inner pipe is 32 × 2 + 43 = 107 mm at maximum if the waves do not mesh with each other, but when meshed, 32 ÷ 2 × 2 + 26 ÷ 2 × 2 + 43 = 101 mm, The maximum is 6 mm smaller. Therefore, the dimension of the outer tube can be reduced by about twice the difference in height between the crest and trough on the outer periphery of the corrugation. Also, when the inner diameter φ36 is arranged at the center and the small-diameter φ24 pipe is arranged on the outer circumference, the degree of compaction of the cross section of the corrugated pipe of the outer pipe due to the fitting of the pipe can be reduced to The difference between the heights of the crests and troughs of the tube with a small inner diameter that abuts is about double. As described above, the corrugated pipe constituting the outer pipe is made compact, so that not only the material cost is reduced, but also the effect of reducing the excavation amount of earth and sand at the time of construction is recognized.

  That is, as shown in FIG. 5A, when the conventional inner pipe 1a is used, the ends of the crests 3 of the inner pipes 1a are in contact with each other in the cross section of the external pipe 7a. That is, the arrangement density of the inner pipes 1 a is determined only by the outermost diameter of the peak portion 3.

  Therefore, in order to insert the required number of inner pipes 1a, it is necessary to increase the outer diameter of the external pipe 7a. Further, if the height of the peak portion 3 is increased in order to increase the compressive strength or the like of the inner pipe 1a, the arrangement density is further reduced, and a larger external pipe 7a is required. Alternatively, the number of inner pipes 1a that can be inserted into the external pipe 7a having a predetermined size is reduced.

  On the other hand, as shown in FIG. 5B, when the inner pipe 1 of the present invention is used, the crests 3 and the troughs 5 of the adjacent inner pipes 1 can be engaged with each other. For this reason, some inner pipes 1 overlap in a section. Therefore, the arrangement density is not determined only by the outer diameter of the inner pipe 1 (the outer diameter of the peak portion), but the distance between the inner pipes 1 can be reduced by the height of the peak portion 3.

  Therefore, the outer diameter of the external pipe 7 required when laying the same number of inner pipes 1 can be reduced as compared with the conventional inner pipe 1a. Alternatively, more inner pipes 1 can be inserted into the external pipe 7 having the same size.

  Further, even when the height of the peak portion 3 is increased to improve the strength, the arrangement density can be reduced by half as compared with the conventional inner pipe 1a, and the strength is secured while ensuring a high arrangement density. It is possible to improve. In addition, since the inner pipes 1 mesh with each other by using the inner pipe 1, it is difficult to insert them one by one into the external pipe. Therefore, as described above, all the inner pipes may be held in a bundled state and collectively inserted into the external pipe 7.

  As described above, according to the first embodiment, it is possible to obtain an inner pipe that can achieve both high laying efficiency and high strength.

  Next, the inner pipe 10 according to the second embodiment will be described. In addition, about the structure which show | plays the same function as the inner pipe | tube 1, the code | symbol similar to FIG. 1 is attached | subjected and the overlapping description is abbreviate | omitted. The inner tube 10 has substantially the same configuration as the inner tube 1, but differs from the inner tube 1 in that a recess 11 is formed at the end of the peak 3 and a protrusion 13 is formed at the bottom of the valley 5. .

  The concave portion 11 and the convex portion 13 are formed over the circumferential direction of the inner tube 10. In addition, the recessed part 11 and the convex part 13 do not necessarily need to be formed one each in the peak part 3 and the trough part 5, and may each be formed two or more.

  FIG. 7A is a diagram showing an axial cross section of the inner tube 10. The concave portion 11 and the convex portion 13 each have a substantially rectangular shape. Here, the width (D in the drawing) of the bottom surface (end surface on the outer peripheral surface side of the peak 3) of the concave portion 11 is the width (E in the drawing) of the end surface (end surface on the outer peripheral surface side of the valley portion 5) of the convex portion 13. Bigger than. Further, since the concave portion 11 and the convex portion 13 have shapes corresponding to each other, the shape of the convex portion 13 can be fitted into the shape of the concave portion 11.

  FIG. 7B is a diagram illustrating a state in which the adjacent inner pipes 10 are engaged with each other. As described above, the peak portion 3 and the valley portion 5 can mesh with each other. At this time, the convex portion 13 of the valley portion 5 is fitted into the concave portion 11 of the peak portion 3. Therefore. The end surface of the peak portion 3 and the bottom surface of the valley portion 5 can be brought into contact with each other.

  In addition, the recessed part 11 and the convex part 13 do not need to be a substantially rectangular shape as illustrated. For example, it may be a shape corresponding to an arc shape, a triangle shape, or the like so as to fit each other.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. Moreover, since the rib-shaped recessed part 11 and the convex part 13 are each formed in the peak part 3 and the trough part 5, higher compressive strength can be obtained. At this time, since the adjacent inner tubes 10 can mesh with each other, a high arrangement density can be obtained.

  The outer surface of the inner pipe 10 itself does not become larger than the outer diameter of the peak portion 3 by making the end surface of the peak portion 3 a concave portion, and the bottom surface of the valley portion 5 is a convex portion, The innermost diameter of the tube 10 is not reduced.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, the cross-sectional shapes of the peak portion 3 and the valley portion 5 do not need to be substantially rectangular as shown in FIG. FIG. 8 is a diagram illustrating a modified example of the peak portion 3 and the valley portion 5. As shown in FIG. 8, the crest 3 and the trough 5 may have a wavy shape in which straight lines and arcs are combined. In this case, the width of the boundary between the straight line portion and the arc portion may be the width of the end face of the peak portion 3 (F in the figure) and the width of the bottom face of the valley portion 5 (G in the figure). Even in this case, the peak portion 3 and the valley portion 5 can be engaged with each other by making the width of the bottom surface of the valley portion 5 (G in the drawing) larger than the width of the end surface of the peak portion 3 (F in the drawing). it can.

  As described above, the crest 3 and the trough 5 may have a corresponding shape so that they can be engaged with each other, and the crest 3 may be narrower than the trough 5. . In the case of a sine wave or the like in which the crest 3 and the trough 5 do not have a flat portion as described above and there is no boundary between a straight line and an arc, for example, What is necessary is just to make the width | variety of the peak part in the center smaller than the width | variety of the trough part in the center of trough depth.

  Moreover, as shown in FIG. 9, you may provide several types (two types in a figure) inner pipe from which a diameter differs in the one external piping 7. As shown in FIG. In the example shown in FIG. 9, an inner tube 1b having a large outer diameter is disposed at the center, and a plurality of inner tubes 1 are disposed on the outer periphery of the inner tube 1b. The arrangement and size of the inner pipe are not limited to the illustrated example.

  The inner tube 1b and the inner tube 1 are corrugated tubes in which peaks and valleys are continuously formed on the outer periphery. The width of the outer periphery of the inner tube 1 b is smaller than the width of the valley on the outer periphery of the inner tube 1. Similarly, the width of the outer periphery of the inner tube 1 is smaller than the width of the outer periphery of the inner tube 1b. Further, the inner pipes 1 and 1b are formed in a wave shape of peaks and valleys having the same pitch. Therefore, the peak shape of the inner tube 1b and the peak shape of the inner tube 1 can be engaged with each other.

  In this case, if the depths of the peaks and valleys of the inner pipes 1 and 1b are substantially the same, the tips of the peaks can be brought into contact with the bottom of the other valley. Therefore, sufficient compressive strength can be secured even for compression of the external pipe 7.

1, 1a, 1b, 10 ......... Inner tube 3 ......... Mountain portion 5 ......... Valley portion 7.7a ......... External piping 9 ......... Main line holding portion 11 ......... Recess portion 13 ......... Protrusion portion

Claims (6)

An inner pipe that is inserted into an external pipe and used.
A corrugated tube made of resin in which peaks and valleys are alternately formed on the outer periphery,
The width of the peak is smaller than the width of the valley,
When a plurality of inner pipes are adjacent to each other, the crests and valleys of adjacent inner pipes mesh with each other, and the tip of the crest of one inner pipe is in contact with the bottom of the trough of the other inner pipe. An inner tube characterized in that it can be contacted.   In the cross section in the axial direction, a flat portion is formed at each of the end portion of the peak portion and the bottom portion of the valley portion, and the width of the flat portion of the peak portion is smaller than the width of the flat portion of the valley portion. The inner pipe according to claim 1.   A concave portion is formed at the end portion of the peak portion, and a convex portion is formed at the bottom portion of the valley portion, and the convex portion is formed when the peak portion and the valley portion of adjacent inner pipes are engaged with each other. The inner pipe according to claim 1, wherein the inner pipe can be fitted into the recess. A method for inserting an inner pipe into an external pipe,
The inner tube is a corrugated tube made of resin in which ridges and valleys are alternately formed on the outer periphery, and the width of the ridges is smaller than the width of the valleys,
A plurality of inner pipes are adjacent to each other, and a tip of the crest of one inner pipe is brought into contact with a bottom of the trough of the other inner pipe, so that each crest and trough of adjacent inner pipes are mutually connected. A method of inserting an inner pipe into an external pipe, characterized in that a plurality of inner pipe bundles that are meshed with each other are bundled, and the bundled inner pipe bundle is inserted into the external pipe. A piping structure,
Buried external piping,
A plurality of first inner pipes inserted through the external pipe;
Comprising
The first inner pipe is a resin corrugated pipe in which crests and troughs are alternately formed on the outer periphery, and the crest has a width smaller than the trough,
In the adjacent first inner pipe, the tip of the peak portion of one first inner pipe is in contact with the bottom of the valley portion of the other first inner pipe, so that the adjacent first inner pipe is A piping structure characterized in that each peak portion and trough portion of each other mesh with each other. In addition to the plurality of first inner pipes, a second inner pipe that is a corrugated pipe having a diameter different from that of the first inner pipe is inserted into the external pipe,
The width of the peak of the first inner pipe is smaller than the width of the valley of the second inner pipe, and the width of the peak of the second inner pipe is the valley of the first inner pipe. Smaller than the width of
The pitch of the valleys of the first inner tube and the pitch of the peaks and valleys of the second inner tube are substantially the same,
6. The piping structure according to claim 5, wherein the crests and troughs of the adjacent first inner pipe and second inner pipe mesh with each other.

Images