JP3059635B2 - Corrugated pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated pipe installed in an existing pipeline to extend an optical cable or the like in the existing pipeline.

[0002]

2. Description of the Related Art In an urban area, a gas pipe is installed in a common ditch formed under the road for the purpose of alleviating traffic congestion caused by excavation of the road, improving cityscape and disaster prevention, or using the underground space for multiple purposes. , Water pipes or steel pipes for laying metal cables for communication. Among such various types of pipes, it has been desired to further add an optical cable or the like in a pipe for laying a metal cable.

That is, the recent development of the optical communication business associated with computers and OA equipment has necessitated the installation of new optical cables. When an optical cable is added in this way, a small-diameter plastic corrugated pipe having flexibility is piped in the existing metal cable pipe to protect the added optical cable, and then the optical cable is laid. I do. Here, the corrugated pipe is a pipe made of a synthetic resin having an axial cross section having a waveform and having a number of annular grooves formed in a longitudinal direction.

When a small diameter corrugated pipe is drawn into an existing pipeline, a retaining member is attached to an end of the corrugated pipe, and the retaining member is pulled into the existing pipeline while being pulled by a wire or the like. doing.

[0005] Various types of such retention members have been put into practical use. For example, those in which a wire net is covered on the end of a corrugated tube and the outer periphery of the net is covered with a finishing tape are known. .

[0006] On the other hand, as another retaining member, as shown in FIG. 10, there is known an eyebolt 1 having an eye (eye: through-hole) 1a at one end. In this case, attach a washer 2 and a nut 3 to the other end of the eyebolt 1,
After the washer 2 side of the eyebolt 1 is inserted into the corrugated pipe, the end of the corrugated pipe 4 is heated and softened, and the softened end is deformed inward by hand or the like while the inner diameter is reduced. The end was processed so as to wrap the washer 2 of the eyebolt 1.

[0007] When a spiral corrugated pipe having a mountain formed in a spiral shape is used as the corrugated pipe, a cylindrical retaining member provided with a screw screwed inside the corrugated pipe is corrugated. Attaching to a pipe and pulling the retaining member into an existing pipeline while pulling the retaining member with a wire or the like is also performed.

[0008]

By the way, if a wire net is used for piping a corrugated pipe in an existing pipeline,
As the outer diameter of the end of the corrugated pipe increases, the end of the corrugated pipe is caught by the inner wall of the existing pipe or an existing object, so that the tensile load when the corrugated pipe is drawn into the pipe increases, and the pipe can be drawn. The length of the corrugated tube is limited. In other words, the length of the corrugated pipe that can be retracted by a single retracting operation is relatively short.

[0009] When a metal cable or the like is laid in an existing pipeline, when a corrugated tube is further drawn into the pipeline, a finishing tape covering the outer periphery of the wire net is used. It is peeled off by friction, and the coating of the existing metal cable or the like is damaged by the exposed wire net. For this reason, there is a problem that the wire net is not always preferable as a retaining member.

On the other hand, when an eyebolt is used, the tensile strength when the eyebolt is attached to the corrugated pipe varies depending on the skill of the operator, and it is not suitable for reliably and firmly pulling in the corrugated pipe. .

Further, in the case of drawing in using a retaining member screwed into a tube with a spiral wave, when the drawing-in operation is performed,
There is a problem that the corrugated pipe and the retaining member may rotate relative to each other, and the retaining member may come off from the corrugated pipe.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and allows a retaining member to be easily attached without increasing the outer diameter of a corrugated pipe. An object of the present invention is to provide a corrugated tube in which a member does not come off.

[0013]

According to the present invention, in order to achieve the above object, a corrugated pipe having a corrugated cross section in the axial direction is provided. Having an anchoring member mounting structure for attaching the anchoring member to an end of the corrugated tube, a portion of the anchoring member mounting structure of the corrugated tube has an inner wall, from one end side to the one end side. A locking groove is formed by a groove-shaped insertion portion extending in the opposite direction to the opening, and a groove-shaped locking portion extending from the insertion portion toward the opening on the one end side, and the periphery of the locking groove is formed. The corrugated tube is recessed in the radial direction, and a reinforcing rib having a height equal to or less than the maximum outer diameter of the corrugated tube is provided on an outer surface near the locking groove.

According to the present invention, in order to achieve the above object, there is provided a corrugated tube having a corrugated cross section in the axial direction, and the retaining member is attached to the corrugated tube when the corrugated tube is pulled in the axial direction. In a corrugated pipe having an anchoring member mounting structure for attaching to an end of the pipe, a part of the anchoring member mounting structure of the corrugated pipe has an inner wall facing from one end side to the opposite end side. An engaging groove formed by a groove-shaped insertion portion extending to the groove and a stop portion of a lateral groove continuously extending in the circumferential direction of the corrugated tube from the insertion portion is formed. The rib is recessed in the radial direction, and a reinforcing rib having a height equal to or less than the outer diameter of the corrugated tube is provided on the outer surface near the locking groove.

The locking groove may be provided at one location at the end of the corrugated pipe, but it is desirable to form at least two locations in the circumferential direction at predetermined intervals.

Preferably, a groove intersecting the axial direction of the corrugated tube is provided between the insertion portion and the locking portion as an intermediate groove.

Preferably, a constricted portion having a groove width such that the protrusion of the protrusion-shaped engaging portion of the retaining member barely passes through the locking portion is formed. For example, a projection (a small recess when viewed from the outside of the corrugated pipe) is provided in the middle of the locking portion and protrudes inside the groove. Thus, the constricted portion can restrict the movement of the engaging portion provided on the retaining member, so that the retaining member once attached does not accidentally come off the corrugated tube due to vibration or the like.

[0018] The locking groove of the mounting structure provided on the corrugated pipe has a groove-shaped insertion portion extending from the end portion in the opposite direction to the end portion on the inner wall of the corrugated tube, and is continuous with the insertion portion. Alternatively, the corrugated pipe may be formed of a stop portion of a lateral groove extending in the circumferential direction.
In this case, it is more preferable to provide a groove-shaped locking portion extending in the axial direction of the corrugated pipe and in the opening direction of the end of the corrugated pipe further following the stop.

[0019] The mounting structure of the corrugated pipe may be provided repeatedly at intervals in the axial direction of the corrugated pipe.

[0020]

The corrugated tube is attached to the retaining member by coupling the locking groove and the engaging means of the retaining member, and forms a mounting structure for the corrugated tube and the retaining member.

At this time, the retaining member is prevented from coming off from the corrugated pipe during the drawing operation into the existing pipeline by making the locking groove substantially L-shaped.

Further, when a narrowing portion for restricting the movement of the engaging portion of the retaining member is provided in the locking groove of the corrugated pipe, particularly the locking portion, the engaging portion is securely locked in the locking groove. You.

[0023]

(Embodiment 1) An embodiment of a corrugated pipe according to the present invention will be described below in detail with reference to FIGS.

The corrugated tube 10 is a tube made of a synthetic resin, for example, polyethylene, having a longitudinal cross-section and a large number of annular grooves 10a formed in a corrugated shape, and has a predetermined interval in the longitudinal direction of the inner surface of the peripheral wall 10b. For example, at the position where 4 m) is placed, locking grooves 11, 11 which are arranged to face each other in the longitudinal direction are formed at four equally spaced positions in the circumferential direction.

Here, since the locking groove 11 is formed on the inner wall surface of the corrugated tube 10 and cannot be seen from the outside of the corrugated tube 10, it corresponds to the locking groove 11 for convenience in FIG. The portion of the peripheral wall 10b was pointed from the outside. Since no waveform is formed in the locking groove 11, the contour of the locking groove 11 is also visible outside the corrugated tube 10.

The locking groove 11 is an L-shaped groove for locking the projecting engagement portions 20b provided at four places of the retaining member 20, and in the corrugated tube 10 shown in FIG. The locking grooves 11, 11 which are arranged to face each other in the longitudinal direction are formed so as to be opposite to each other so that the retaining member 20 can be attached from the side. Further, a corrugated pipe 10 is provided before and after the locking grooves 11, 11 which are opposed to each other at a predetermined interval in the longitudinal direction.
Are formed. The cutting section 12 is used to cut the corrugated pipe 10 into an appropriate length according to the use condition. A groove is formed on the inner peripheral side of the cut portion 12 in the circumferential direction.

Here, as shown in FIG. 1, the retaining member 20 has a substantially spindle-shaped main body 20a whose both ends have a substantially cone shape (cone) or a substantially truncated cone shape.
Each engaging portion 20b is provided corresponding to the locking groove 11 formed at four places of the corrugated tube 10. Further, two through holes 2 penetrating the main body 20a in the radial direction at both ends of the main body 20a.
0c and 20d are provided. One end of a lead wire 21 for pulling is connected to the through hole 20c, and one end of a lead cord 22 for drawing in a cable is connected to the other through hole 20d.

The locking groove 11 is developed by cutting the corrugated pipe 10 along the longitudinal direction, and is extended in the longitudinal direction of the corrugated pipe 10 as shown in FIG. 2 showing the inner surface of the peripheral wall 10b. 20, an insertion portion 11a for guiding an engagement portion 20b provided on
Further, the peripheral wall 10b is connected to the inner portion of the insertion portion 11a.
A stop portion 11b extending in the circumferential direction of the inner surface, and a locking portion 11c which is folded back from the stop portion 11b in parallel with the insertion portion 11a.
The engaging portion 11c has a protrusion 11 which projects in the width direction of the groove and restricts the movement of the engaging portion 20b to the extent that the engaging portion 20b provided on the retaining member 20 can barely pass.
d and 11d are provided.

As shown in FIG. 1, the corrugated tube 10 is further provided with reinforcing ribs 10c formed in various shapes in the vicinity where the respective locking grooves 11 are formed. Further, the outer surface of the peripheral wall 10b adjacent to the insertion portions 11a, 11a located at circumferentially opposite positions is formed into planes 10d, 10d parallel to each other.

When piping the corrugated pipe 10 in an existing pipeline, the retaining member 20 is attached to the end of the corrugated pipe 10 as follows. Here, the movement of the retaining member 20 in the following description is indicated by arrows (,,) on the retaining member 20 of FIG. 1 for convenience of description.

First, the retaining member 20 is inserted from the end of the corrugated tube 10 so that each engaging portion 20b is aligned with the insertion portion 11a of each locking groove 11, and each engaging portion 20b is inserted in the direction of the arrow in the figure. While the guide 20b is guided by the insertion portion 11a, the retaining member 20 is connected to the corrugated tube 1 until each engagement portion 20b abuts on the wall surface of the stop portion 11b.
Push it into 0.

Next, when each engaging portion 20b abuts against the wall surface of the stopping portion 11b, the retaining member 20 is turned clockwise as shown by an arrow in the drawing, and the engaging portion 20b is moved to the stopping portion 1b.
Move along 1b.

Next, when each engaging portion 20b abuts against the wall surface of the locking portion 11c, the retaining member 20 is pulled back as shown by the arrow in the drawing. Then, the retaining member 20
Each of the engaging portions 20b is pulled into the engaging portion 11c, and goes into the innermost portion of the engaging portion 11c beyond the protrusions 11d, 11d, so that the retaining member 20 is attached to the end of the corrugated tube 10. .

The corrugated pipe 10 with the retaining member 20 attached to the end in this way is pulled by the lead wire 21 and is piped into the existing pipeline.

At this time, the retaining member 20 causes the respective engaging portions 20b to be located at the innermost portion of the locking portion 11c by the pulling force applied from the lead wire 21, and also causes the retaining member 20 to vibrate due to vibration or the like. Even if a relatively small force acts in the opposite direction to that of the opening, the movement of each engaging portion 20b is restricted by the protrusions 11d. For this reason, each engaging portion 20b is securely held in the locking portion 11c, and the retaining member 20 does not accidentally come off the corrugated tube 10.

Therefore, in the corrugated pipe of the present invention,
The corrugated tube 10 and the retaining member 20 are maintained in the correct engagement state until the corrugated tube 10 starts to be pulled in.

In the corrugated pipe according to the present invention, when the corrugated pipe 10 is drawn into the existing pipeline, the corrugated pipe 10 and the retaining member 20 do not rotate relative to each other. There is no possibility that the tube 20 comes off the corrugated tube 10.

Then, when the work of drawing into the existing pipeline is completed, the corrugated pipe 1 is operated in the reverse manner to the above.
The retention member 20 can be removed from zero.

(Other Embodiments) Here, it goes without saying that the locking grooves formed in the corrugated tube are not limited to those of the above-described embodiment. For example, as shown in FIG. 3, the locking grooves 16, 16 opposed to each other are formed between the cut portions 15, 15, and as shown in FIG. The locking grooves 17, 18 to be formed may be interchanged. Further, as shown in FIGS. 5 and 6, stop portions 11b, 11b and locking portions 11c, 11c may be continuously provided at both ends of the insertion portion 11a, and the insertion portion 11a may be shared. In addition, locking groove 1
1 is an insertion part 11a and a stop part 11b as shown in FIGS.
It is not necessary to be composed of three parts, namely, the locking part 11c and the locking groove 11, as shown in FIG. 8, the locking groove 11 is sufficient with the insertion part 11a and the locking part 11c provided continuously therewith. In FIG. 8, the locking portion 11c is at an angle of 90 degrees or 9
They are connected at an angle of 0 degrees or less. Further, as shown in FIG. 7, the intermediate groove 30 may be continuously provided at an angle larger than 90 degrees with respect to the insertion portion 11a, and the locking portion 11c may be provided continuously therewith. Furthermore, as shown in FIG. 9, an intermediate groove 30 may be provided between the insertion portion 11a and the locking portion 11c in a curved manner.

Although the locking portion 11c is provided in FIG. 1 of the first embodiment, since the stopping portion 11b is provided at a right angle to the insertion portion 11a, the locking portion 11c is not provided in this case. You may.

The insertion portion 11a does not need to be provided in parallel with the axial direction of the corrugated tube, as in the case of the locking portion 11c, and may be provided inclining in the axial direction of the corrugated tube.

In FIGS. 3 and 4, the portions corresponding to the locking grooves 11 of the above embodiment are denoted by the same reference numerals, and the locking grooves 1
Detailed description of 7, 18 is omitted.

At this time, if the retaining grooves 17 and 18 shown in FIG. 4 are used, the corrugated pipe is cut along the two-dot chain line A or the two-dot chain line B according to the direction in which the retaining member 20 is attached. For example, when attaching the retaining member 20 to the corrugated pipe from the left side in FIG. 4, the corrugated pipe is cut along the two-dot chain line A,
Each engaging portion 20b is inserted into the locking groove 18. On the other hand, when attaching the retaining member 20 from the right side, the corrugated pipe is cut along the two-dot chain line B, and each engaging portion 20 b is inserted into the locking groove 17.

[0044]

As is apparent from the above description, according to the present invention, the retaining member can be easily attached without increasing the outer diameter of the corrugated pipe, and the retaining member is drawn into the existing pipeline. Provided is a corrugated tube in which the retaining member does not come off during operation.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a corrugated pipe according to the present invention.
It is the perspective view which showed the state which attaches a retention member to a corrugated pipe.

FIG. 2 is a development view of a locking groove formed in the corrugated tube of FIG.

FIG. 3 is a development view showing another modification of the locking groove formed in the corrugated tube.

FIG. 4 is a developed view showing still another modified example of the locking groove formed in the corrugated tube.

FIG. 5 is a development view showing another example of the locking groove.

FIG. 6 is a developed view showing still another example of the locking groove.

FIG. 7 is a development view showing still another modified example of the locking groove formed in the corrugated tube.

FIG. 8 is a development view showing another example of the locking groove.

FIG. 9 is a development view showing still another example of the locking groove.

FIG. 10 is a front view for explaining a conventional corrugated pipe and showing a part of the corrugated pipe in a cutaway manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Corrugated pipe 10b Peripheral wall 11 Lock groove 11a Insert section 11b Stop section 11c Lock section 11d Projection 16 Lock groove 16a Insert section 16b Stop section 16c Lock section 16d Projection 17, 18 Lock groove 17a, 18a Insert section 17b , 18b Stopping part 17c, 18c Locking part 17d, 18d Projection 20 Retaining member 20a Retaining member main body 20b Engaging part 20c Through hole 20d Through hole 21 Lead wire 22 Lead cord 30 Intermediate groove

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-52-149842 (JP, A) JP-A-61-89478 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 11/11 F16L 1/00 H02G 3/04 301

Claims (3)

(57) [Claims] 1. A corrugated tube (10) having a corrugated cross section in the axial direction, wherein a retaining member (20) is attached to an end of the corrugated tube when the corrugated tube is pulled in the axial direction. A crevice pipe having a retaining member mounting structure for inserting a groove-like insertion extending from one end side of the corrugated pipe in a direction opposite to the one end side to an inner wall thereof. A locking groove (11) is formed which includes a portion (11a) and a groove-shaped locking portion (11c) extending from the insertion portion toward the opening on the one end side, and the locking groove (11) is formed. The periphery is recessed in the radial direction of the corrugated tube, and the locking groove (11) is provided.
A reinforcing rib (10c) having a height equal to or less than a maximum outer diameter of the corrugated pipe is provided on an outer surface near the corrugated pipe. 2. A corrugated tube (10) having a corrugated cross section in the axial direction, wherein a retaining member (20) is attached to an end of the corrugated tube when the corrugated tube is pulled in the axial direction. A crevice pipe having a retaining member mounting structure for inserting a groove-like insertion extending from one end side of the corrugated pipe in a direction opposite to the one end side to an inner wall thereof. A locking groove (11) is formed by a portion (11a) and a stop portion (11b) of a lateral groove continuously extending from the insertion portion in the circumferential direction of the corrugated tube, and around the locking groove (11). Is recessed in the radial direction of the corrugated tube, and a reinforcing rib (10c) having a height equal to or less than the outer diameter of the corrugated tube is provided on an outer surface near the locking groove (11). A corrugated pipe characterized by the following. 3. The corrugated pipe according to claim 1, wherein a portion having the same structure as the retaining member mounting structure provided on the corrugated pipe is repeatedly provided at intervals in an axial direction of the corrugated pipe. A corrugated pipe.