JP2019161684A - Inner pipe for insertion and insertion method - Google Patents

Abstract

To provide an inner pipe for insertion and an insertion method allowing sure insertion of the fire-resistant inner pipe for insertion inside a pipeline with a cable installed therein.SOLUTION: An inner pipe 106 for insertion of the present invention is inserted inside a pipeline 102 with an OF cable 104 installed therein, formed of a fire-resistant material, and having a half-split structure sandwiching the OF cable inside.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an inner pipe for insertion inserted into a pipe line in which a cable is laid and an insertion method.

  Under the bridge over the river etc., for example, a pipeline is installed over a long distance of several hundred meters. The pipe is made of a resin such as FRP (Fiber-Reinforced Plastics), for example, and an OF (Oil Filled) cable such as a high-voltage electric wire is laid inside the pipe.

  In such a pipeline, when the OF cable is ignited due to electric leakage or the like, the pipeline as the resin itself burns, and there is a possibility that a flame spreads to the outside of the pipeline and a fire occurs. Therefore, assuming such a situation, it is necessary to take some disaster prevention measures in the pipeline where the cable is laid.

  Patent Document 1 describes a mounting method in which a cable protective material is mounted on a cable in a pipeline that accommodates the cable. This attachment method involves inserting the cable protection material through the opening of the pipeline over the cable to be protected, and pulling the cable protection material installation jig in the pipeline along the cable to be protected. The cable is wrapped around.

  According to the mounting method disclosed in Patent Document 1, it is possible to mount a cable protective material on a cable in a pipeline without affecting the existing cable by wrapping the cable with the cable protective material.

JP 2010-74911 A

  However, the technique described in Patent Document 1 does not protect the pipeline itself, but merely wraps the cable in the pipeline with a cable protection material. For this reason, even if it is going to apply the technique of patent document 1 in order to implement | achieve a disaster prevention measure, in the situation where a cable ignites, it cannot prevent that a pipe line itself burns, but it can prevent the occurrence of a fire. Have difficulty.

  In view of such problems, an object of the present invention is to provide an insertion inner pipe and an insertion method capable of reliably inserting a flame retardant insertion inner pipe inside a pipe line in which a cable is laid.

  In order to solve the above-described problems, a typical configuration of an insertion inner pipe according to the present invention is an insertion inner pipe that is inserted inside a pipeline in which a cable is laid, and is made of a flame-retardant material. And having a halved structure that sandwiches the cable inside.

  In the above configuration, the flame-retardant and half-structured inner pipe for insertion is inserted inside the pipe. For this reason, as an example, when the pipe is made of resin such as FRP or vinyl chloride, and the cable is an OF cable such as an electric wire, it is difficult to insert the cable inside the pipe in a situation where the OF cable is ignited due to electric leakage or the like. The flammable inner tube can prevent the pipeline from burning. Therefore, even if the OF cable is ignited, the flame does not spread to the outside of the pipeline, and a fire can be prevented. Moreover, since the inner pipe for insertion has a half structure, the cable can be sandwiched into the pipe while avoiding the existing cable.

  Of course, it is necessary for the insertion inner tube to be flame retardant. However, if the temperature of the insertion inner tube rises, the tube will also ignite. Therefore, it is preferable that the inner tube for insertion has a high thermal conductivity, for example, a metal is preferable. Thereby, since heat can be diffused in the front-rear direction from the ignition position of the OF cable, it is possible to prevent the temperature from rising to the ignition point of the pipeline (FRP). Moreover, since long-term installation is planned, the material strong against corrosion is preferable. Considering these, it is preferable to use aluminum or an aluminum alloy for the inner tube for insertion.

  The inner tube for insertion may include a rib formed on the outer surface thereof and extending in the axial direction. Thus, by forming the axial rib on the outer surface of the inner tube for insertion, the contact area between the inner tube for insertion and the pipe line (outer tube) can be reduced. For this reason, the friction at the time of inserting the inner pipe for insertion inside a pipe line can be reduced.

  A plurality of the above-mentioned inner pipes are inserted and inserted into the inside of the conduit, and a distal end member made of resin is attached to the distal end of the leading insertion inner pipe, and the distal end member is directed toward the distal end. It is good to be formed in the taper shape which becomes thin.

  In the above configuration, the resin-made tip member is attached to the tip of the leading insertion inner tube among the many insertion inner tubes. Since the resin-made tip member is softer than the inner tube for insertion, damage to the cable can be prevented. In addition, since the tip of the tip member is thin due to the tapered shape, the leading insertion inner tube can be easily inserted between the cable and the conduit.

  A hole into which a pin is inserted is formed on the end surface of the inner tube for insertion described above, and the positional displacement between the end surfaces of the adjacent inner tubes to be inserted is restricted by the pin inserted into the hole. It is good to have.

  When inserting a large number of insertion inner pipes into the pipeline while adding them, the insertion inner pipes are added and pushed from behind, so that the load for press-fitting becomes extremely large at a long distance. For this reason, if adjacent inner pipes are displaced from each other, the end faces may be bitten. In particular, when a rib is provided on the inner tube, a thick part and a thin part are formed, and therefore, when the thin parts come into contact with each other, they are easily bitten. On the other hand, since the positional displacement (rotational deviation) of the end surfaces of the adjacent inner tubes for insertion is regulated by the pins, the end surfaces of the inner tubes for insertion can be reliably brought into contact with each other. The inner pipe can be reliably pushed into the inside of the pipe line.

  In order to solve the above-described problem, a typical configuration of the insertion method according to the present invention is an insertion method in which the above-described inner pipe for insertion is inserted into the inside of a pipe line in which a cable is laid. Prepare a large number of inner pipes for insertion, sandwich the cable inside by the half structure of the leading insertion inner pipe, insert the leading insertion inner pipe inside the conduit, and The cable is characterized in that the cable is sandwiched inside by a half-split structure, and the subsequent insertion inner pipe is added to the leading insertion inner pipe and is sequentially pushed into the inside of the conduit.

  The components corresponding to the technical idea of the inner tube for insertion described above and the description thereof are also applicable to this method. That is, by inserting a large number of unit-length inner pipes and sequentially pushing them into the pipe, it is possible to insert the flame-retardant inner pipe into the pipe. For this reason, when the pipe is an FRP pipe and the cable is an OF cable such as an electric wire, it is possible to prevent the pipe from burning in a situation where the OF cable ignites due to electric leakage or the like.

  ADVANTAGE OF THE INVENTION According to this invention, the inner tube for insertion and the insertion method which can insert a flame-retardant inner tube for insertion reliably inside the pipe line by which the cable was laid can be provided.

It is a figure which shows the pipe line in which the inner pipe for insertion in embodiment of this invention is inserted. It is a figure which shows the AA cross section of a pipe line in detail. It is a figure which shows the procedure in which the inner pipe for insertion is sequentially pushed inside the pipe line. It is a figure which shows a mode that the subsequent inner pipe for insertion is added to the first inner pipe for insertion. It is a figure which shows a mode that the inner tube for insertion of the head and the subsequent inner tube for insertion are connected. It is a figure explaining a tip member. It is a figure which shows the inner tube for insertion in a modification.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram showing a pipe line into which an insertion inner pipe is inserted in an embodiment of the present invention. FIG. 1A is a diagram showing a pipe line 102 installed under the bridge 100. FIG.1 (b) is a figure which shows typically the AA cross section of the pipe line 102 of Fig.1 (a). As shown in FIG. 1B, a plurality of pipelines 102 are installed under the bridge 100, but in FIG. 1A, one pipeline 102 is representatively shown.

  Under the bridge 100 shown in FIG. 1A, for example, a pipeline 102 is installed over a long distance of several hundreds of meters. The pipe line 102 is made of a resin such as FRP, and a high-voltage electric wire (OF cable 104) or the like is laid therein. Such a pipe line 102 may be installed not only under the bridge 100 but also in the ground. In such a conduit 102, when the OF cable 104 is ignited due to electric leakage or the like, the resin conduit 102 itself burns, flame spreads outside the conduit 102, and finally a fire occurs. There can be.

  Therefore, in this embodiment, as shown in FIG. 1A, a disaster prevention measure is adopted in which a flame-retardant inner tube 106 for insertion is inserted inside the conduit 102. Here, the case where the inner pipe 106 for insertion is inserted inside the pipe line 102 located between the manholes 110 and 112 is illustrated.

  In this case, a large number of inner pipes 106 for insertion are prepared. Next, although details will be described later, the inner pipe 106 for insertion is sequentially pushed into the inside of the pipe 102 from one end 114 of the pipe facing the manhole 110 (see FIG. 3).

  This operation is repeated until the leading insertion inner tube 106 reaches the other end 116 of the conduit 102 facing the manhole 112, whereby the flame retardant insertion inner tube 106 is inserted inside the conduit 102. Is done. The unit length of the inner tube for insertion 106 may be set as appropriate in consideration of the overall length of the conduit 102, the weight of the inner tube for insertion 106, the work efficiency at the time of insertion, and the like.

  Moreover, in order to implement disaster prevention measures, it is of course necessary that the insertion inner pipe 106 is flame retardant. However, if the temperature of the inner pipe 106 for insertion rises, the pipe line 102 will also ignite. Therefore, the material of the insertion inner tube 106 is preferably a material having high thermal conductivity, for example, metal. According to such an inner pipe 106 for insertion, since heat can be diffused in the front-rear direction from the ignition position of the OF cable 104, it is possible to prevent the temperature from rising to the ignition point of the pipe line 102 that is FRP. Furthermore, since the insertion inner pipe 106 is scheduled to be installed for a long time inside the pipe 102, a material resistant to corrosion is preferable. Considering these, it is more preferable to use aluminum or an aluminum alloy for the inner pipe 106 for insertion.

  Here, the inside of the conduit 102 into which the insertion inner tube 106 is inserted is a gap 118 between the conduit 102 and the OF cable 104 shown in FIG. As shown in FIG. 1B, the insertion inner pipe 106 is separated from the OF cable 104 at the upper part of the pipe line 102 and at the lower part of the pipe line 102 with the OF cable 104 in the gap 118 of the pipe line 102. It arrange | positions so that the path | route 102 may be separated. That is, the inner pipe 106 for insertion is a flame retardant inner pipe that serves as a fire wall that protects the pipe 102 itself, rather than wrapping the OF cable 104, and forms a double pipe together with the pipe 102 that serves as the outer pipe. To do.

  FIG. 2 is a diagram showing the AA cross section of the pipe line 102 in more detail. As shown in the drawing, an insertion inner pipe 106 for protecting the pipe 102 itself is inserted inside the pipe 102 where the OF cable 104 is laid, that is, in the gap 118.

  The inner tube 106 for insertion has a half structure that can be separated into a semi-cylindrical upper portion 120 and a lower portion 122. The inner pipe 106 for insertion becomes a cylindrical inner pipe by connecting the upper part 120 and the lower part 122.

  A rail groove 126 is formed at one end 124 of the lower portion 122. One end portion 128 having a substantially circular cross section in the upper portion 120 is slid and connected to the rail groove 126. On the other hand, a rail groove 132 is formed in the other end portion 130 of the upper portion 120. The other end portion 134 having a substantially circular cross section in the lower portion 122 is slidably connected to the rail groove 132. In this way, the upper part 120 and the lower part 122 are connected to form a cylinder (see FIG. 4).

  Further, ribs 136 and 138 extending in the axial direction are formed on the outer surfaces of the semi-cylindrical upper portion 120 and lower portion 122, respectively. Here, as shown in FIG. 2, the rib 138 of the lower portion 122 of the insertion inner tube 106 is in contact with the conduit 102, and the thin portion 140 is not in contact with the conduit 102.

  When the OF cable 104 is bent upward due to aging or the like, the insertion inner pipe 106 is not in contact with the rib 138 of the lower part 122 but the rib 136 of the upper part 120 is in contact with the pipe line 102. At this time, the thin portion 142 does not contact the conduit 102.

  As described above, by forming the ribs 136 and 138 on the outer surfaces of the upper portion 120 and the lower portion 122, the contact area between the insertion inner tube 106 and the conduit 102 can be reduced, and the insertion portion can be inserted inside the conduit 102. Friction when inserting the inner tube 106 can be reduced. Moreover, since the thin parts 140 and 142 are formed by forming the ribs 136 and 138, the weight can be reduced accordingly.

  Even if the ribs 136 and 138 are not formed, the outer surface of the upper part 120 and the lower part 122 is subjected to a fluororesin coating process to reduce friction between the insertion inner pipe 106 and the pipe 102. it can. Furthermore, the present invention is not limited to this, and friction can be reduced by applying a lubricant such as polywater (registered trademark) to the outer surfaces of the upper portion 120 and the lower portion 122.

  FIG. 3 is a diagram showing a procedure for sequentially pushing the inner pipe 106 for insertion into the inside of the pipe line 102. FIG. 3A is a perspective view showing a tube pressing device 144 installed in a manhole 110 (see FIG. 1A) located on one end 114 side of the conduit 102, and is inserted inside the conduit 102. A state in which the inner pipe 106 is pushed in is shown. FIG. 3B is an enlarged view of a part of FIG.

  As shown in FIG. 3A, the tube pushing device 144 includes support bases 146 and 148, a hydraulic cylinder 150, and a tube pushing member 152. The support bases 146 and 148 are installed on the floor surface of the manhole 110 and support the hydraulic cylinder 150. The tube pressing member 152 is attached to the tip of the rod 154 of the hydraulic cylinder 150, and has a horseshoe-shaped pressing portion 156 as shown in FIG.

  The pressing part 156 has a curved shape along the outer periphery of the OF cable 104 and is disposed so as to face the end surface 158 of the insertion inner pipe 106. For this reason, when the rod 154 of the hydraulic cylinder 150 is pushed out toward the conduit 102, the pressing portion 156 of the tube pressing member 152 attached to the tip of the rod 154 comes into contact with the end surface 158 of the insertion inner tube 106. Is pressed toward the conduit 102.

  After pushing the rod 154 and pushing the inner tube 106 for insertion, the rod 154 is pulled and the next inner tube 106 for insertion is added. By repeating such an operation until the leading insertion inner pipe 106 reaches the other end 116 (see FIG. 1A) of the pipe line 102, a plurality of flame-retardant inserts are inserted inside the pipe line 102. The inner tube 106 can be inserted.

  FIG. 4 is a diagram illustrating a state in which the subsequent insertion inner pipe 106 is added to the leading insertion inner pipe 106. The leading insertion inner tube 106 shown in FIG. 4A is formed into a cylinder by sandwiching the OF cable 104 inside, and has already been inserted inside the conduit 102. The rear end face 162 of the leading insertion inner pipe 106 has not yet entered, and is in a position protruding from one end 114 of the pipe line 102.

  First, the lower portion 122 of the subsequent insertion inner tube 106 is arranged along the lower side of the OF cable 104 with respect to such a leading insertion inner tube 106, and further, the leading insertion inner tube 106. It is made to contact | abut to the end surface 162. Then, as shown in FIG. 4A, the upper portion 120 of the subsequent insertion inner pipe 106 is arranged so as not to overlap the lower portion 122 from the upper side of the OF cable 104.

  Subsequently, as shown by an arrow in FIG. 4B, the upper portion 120 of the subsequent insertion inner tube 106 is slid toward the lower portion 122, and one end portion 128 of the upper portion 120 (see FIG. 2). Is inserted into a rail groove 126 formed at one end 124 of the lower portion 122. Then, as shown in FIG. 4C, the upper portion 120 is further slid to bring the end surface 164 of the upper portion 120 into contact with the end surface 162 of the leading insertion inner tube 106.

  In this way, the succeeding inner pipe 106 is connected by sliding the upper part 120 and the lower part 122 of the half structure. As a result, the insertion inner tube 106 sandwiches the OF cable 104 inside, and the end surface 164 abuts on the end surface 162 of the leading insertion inner tube 106 (see FIG. 5), and is added to the insertion inner tube 106. .

  FIG. 5 is a diagram showing a state in which the leading insertion inner pipe 106 and the subsequent insertion inner pipe 106 are connected. FIG. 5 shows a state in which the insertion inner pipes 106 and 106 are connected to each other by the connecting metal fitting 160 subsequent to FIG.

  The inner pipes 106, 106 for insertion are in a state in which the end faces 162, 164 are in contact with each other as shown. Further, in the inner pipes 106 and 106 for insertion, grooves 166 and 168 are formed in the rib 136 of the upper portion 120, respectively, and grooves 170 and 172 are formed in the rib 138 of the lower portion 122, respectively.

  Like the upper metal fitting 174 and the lower metal fitting 176, the connection metal fitting 160 has a separable half structure. The upper metal fitting 174 and the lower metal fitting 176 are respectively connected so as to extend over the grooves 166 and 168 and the grooves 170 and 172 of the adjacent inner pipes 106 and 106 for insertion as shown in the figure.

  The upper metal fitting 174 has beads 178 and 180. These beads 178 and 180 are bent inward so as to fit into grooves 166 and 168 formed in the rib 136 of the upper portion 120 of the inner pipes 106 and 106 for insertion. Grooves 182 and 184 are formed outside the beads 178 and 180.

  The lower metal fitting 176 has beads 186 and 188. These beads 186 and 188 are bent inwardly so as to fit into grooves 170 and 172 formed in the rib 138 of the lower portion 122 of the inner pipes 106 and 106 for insertion. Grooves 190 and 192 are formed outside the beads 186 and 188.

  When attaching the connecting metal fitting 160 to the insertion inner pipes 106, 106, the upper metal fitting 174 is brought closer to the insertion inner pipes 106, 106 from above, and the beads 178, 180 of the upper metal fitting 174 are inserted into the grooves 166 of the upper portion 120. 168. Further, the lower metal fitting 176 is made to approach the insertion inner pipes 106 and 106 from below, and the beads 186 and 188 of the lower metal fitting 176 are fitted into the grooves 170 and 172 of the lower portion 122.

  Next, the outer grooves of the connecting metal fitting 160, that is, the grooves 182 and 184 of the upper metal fitting 174 and the grooves 190 and 192 of the lower metal fitting 176 are tightened with a band (not shown). In this manner, the connecting metal fitting 160 is attached so as to straddle the adjacent inner pipes 106, 106, and the inner pipes 106, 106 can be connected (see FIG. 3A).

  FIG. 6 is a diagram illustrating the tip member 196. A resin-made tip member 196 is attached to the tip 194 of the leading insertion inner tube 106. The tip member 196 has a half structure that can be separated into an upper member 198 and a lower member 200. The upper member 198 and the lower member 200 are formed in a tapered shape that becomes thinner toward the tips 202 and 204, respectively, as shown.

  On the base side of the upper member 198 and the lower member 200, grooves 206 and 208 are formed on the outside. In these grooves 206 and 208, the bead 180 of the upper metal fitting 174 and the bead 188 of the lower metal fitting 176 of the connecting metal fitting 160 are fitted, respectively. Further, as shown in the drawing, a groove 210 formed in the rib 136 of the upper portion 120 and a groove 212 formed in the rib 138 of the lower portion 122 are positioned on the distal end 194 side of the leading insertion inner tube 106. is doing. The bead 178 of the upper metal fitting 174 and the bead 186 of the lower metal fitting 176 of the connecting metal fitting 160 are fitted in the grooves 210 and 212 of the inner pipe for insertion 106, respectively.

  When the resin-made tip member 196 is attached to the tip 194 of the insertion inner tube 106, the upper member 198 and the lower member 200 of the tip member 196 are adjacent to the upper portion 120 and the lower portion 122 of the insertion inner tube 106, respectively. Arrange as follows.

  Then, the upper metal member 174 is approached from the upper side with respect to the upper member 198 of the tip member 196 and the upper portion 120 of the inner tube 106 for insertion, and the beads 178 and 180 of the upper metal member 174 are inserted into the groove 210 and the upper member of the upper portion 120. It fits into the groove 206 of 198, respectively. Further, the lower metal member 176 is approached from the lower side with respect to the lower member 200 of the distal end member 196 and the lower portion 122 of the insertion inner tube 106, and the beads 186 and 188 of the lower metal member 176 are further connected to the lower portion 122. The groove 212 and the groove 208 of the lower member 200 are respectively fitted.

  Next, the grooves 182 and 184 of the upper metal fitting 174 and the grooves 190 and 192 of the lower metal fitting 176, which are the outer grooves of the connecting metal fitting 160, are tightened with bands (not shown). In this way, the resin-made distal end member 196 can be attached to the distal end 194 of the insertion inner tube 106 using the connection fitting 160.

  In this way, since the resin tip member 196 is softer than the metal insertion inner tube 106, damage to the OF cable 104 can be prevented. Further, since the tips 202 and 204 of the tip member 196 are thin due to the taper shape, the leading insertion inner tube 106 can be easily inserted between the OF cable 104 and the conduit 102.

  FIG. 7 is a view showing an insertion inner pipe 106A in a modified example. The inner pipe for insertion 106A is a modification of the inner pipe for insertion 106 described above in that holes 218 and 220 into which pins (dowels) 214 and 216 are inserted are formed on the end surface 162A. A hole 218 into which the pin 214 is inserted is formed in one end portion 124 of the lower portion 122A. The hole 220 into which the pin 216 is inserted is formed in the other end portion 130 of the upper portion 120A.

  When the subsequent insertion inner pipe 106 is added to the insertion inner pipe 106A of the modified example, holes for inserting the pins 214 and 216 are formed in the end surface 164 (see FIG. 5) of the insertion inner pipe 106, and the pins 214, What is necessary is just to insert 216 over the adjacent inner pipes 106 and 106 for insertion.

  When inserting a large number of insertion inner pipes 106, 106 into the pipe 102 while adding them, the insertion inner pipes 106, 106 are added and pushed from the back, so that the load for press-fitting is extremely large at a long distance. growing. For this reason, if the adjacent inner pipes 106 and 106 for insertion will shift | deviate, there exists a possibility that an end surface may bite.

  On the other hand, the positional displacement (rotational deviation) between the end surfaces of the insertion inner pipes 106A and 106 that are adjacent to each other by the pins 214 and 216 is regulated. Accordingly, the end surfaces of the inner pipes 106A and 106 for insertion can be reliably brought into contact with each other, and a large number of the inner pipes 106A and 106 for insertion can be reliably pushed into the inside of the duct 102.

  As described above, according to the present embodiment, a large number of flame retardant and half-structured inner pipes 106 for insertion can be reliably inserted into the inside of the duct 102 where the OF cable 104 is laid. Disaster prevention measures can be realized.

  That is, in a situation where the OF cable 104 is ignited due to electric leakage or the like, it is possible to prevent the pipe line 102 from being burned by the insertion inner pipe 106 serving as a flame-retardant fire wall inserted inside the pipe line 102. Therefore, even if the OF cable 104 is ignited, the flame does not spread to the outside of the pipe line 102 and a fire can be prevented. Further, since the inner pipe 106 for insertion has a half structure, the OF cable 104 can be sandwiched inside to form a pipe while avoiding the existing OF cable 104.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used as an inner tube for insertion and an insertion method that are inserted inside a pipeline in which a cable is installed.

DESCRIPTION OF SYMBOLS 100 ... Bridge, 102 ... Pipe line, 104 ... OF cable, 106, 106A ... Inner pipe | tube for insertion, 110, 112 ... Manhole, 114 ... One end of a pipe line, 116 ... The other end of a pipe line, 118 ... Gap of a pipe line , 120, 120A ... upper portion of the inner tube for insertion, 122, 122A ... lower portion of the inner tube for insertion, 124 ... one end portion of the lower portion, 126, 132 ... rail groove, 128 ... one end portion of the upper portion, 130 ... the other end of the upper part, 134 ... the other end of the lower part, 136 ... the rib of the upper part, 138 ... the rib of the lower part, 140, 142 ... the thin part, 144 ... the tube pressing device, 146, 148 ... support base, 150 ... hydraulic cylinder, 152 ... pipe pressing member, 154 ... rod, 156 ... pressing part, 158, 162, 162A, 164 ... end face of the inner pipe for insertion, 160 ... coupling fitting, 166, 168 170 172, 210, 212 ... rib groove, 174 ... upper metal fitting of coupling metal, 176 ... lower metal fitting of coupling metal, 178, 180 ... bead of upper metal fitting, 182, 184 ... groove of upper metal fitting, 186, 188 ... lower Side metal fitting bead, 190, 192 ... lower metal fitting groove, 194 ... leading end of inner tube for insertion, 196 ... tip member, 198 ... upper member of tip member, 200 ... lower member of tip member, 202 ... upper Tip of member, 204 ... Tip of lower member, 206 ... Groove of upper member, 208 ... Groove of lower member, 214, 216 ... Pin, 218, 220 ... Hole

Claims (5)

An inner pipe for insertion that is inserted into the inside of a pipeline in which the cable is laid,
An inner pipe for insertion, which is made of a flame retardant material and has a halved structure for sandwiching the cable inside.   The inner tube for insertion according to claim 1, wherein the inner tube for insertion includes a rib formed on an outer surface thereof and extending in an axial direction. The insertion inner pipe is inserted into the inside of the pipeline by adding a plurality of pipes,
A resin tip member is attached to the tip of the leading inner tube for insertion,
The inner tube for insertion according to claim 1 or 2, wherein the tip member is formed in a tapered shape that becomes thinner toward the tip. A hole into which a pin is inserted is formed on the end surface of the inner tube for insertion,
4. The displacement of the end faces of the inner pipes for insertion adjacent to each other after being connected is regulated by the pins inserted into the holes. 5. Inner tube for insertion. An insertion method for inserting the insertion inner pipe according to any one of claims 1 to 4 into an inner side of a pipe line in which a cable is laid,
Prepare a large number of inner tubes for insertion of unit length,
The cable is sandwiched inside by a half structure of the leading insertion inner tube, and the leading insertion inner tube is inserted inside the conduit,
The cable is sandwiched inside by a half structure of a subsequent insertion inner pipe, and the subsequent insertion inner pipe is added to the leading insertion inner pipe and sequentially pushed into the inside of the conduit. How to insert.

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