JPH0523632Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a manhole structure used for conduit-type power transmission lines.

(Conventional technology) For major power transmission lines where the number of cables is expected to increase in the future, the conduit method is often used instead of the direct burial method to facilitate cable replacement and maintenance. This conduit method involves burying reinforced concrete pipes underground and running cables into them.
Manholes will be provided every 300m.

In such manholes for power transmission conduits, the lower side wall through which the cables pass has a large number of holes regularly provided in advance for attaching cable rack brackets, and the footholds are placed in a separate side wall. is attached to.

(Problem to be solved by the invention) However, since the above-mentioned foothold hardware is generally formed in a U-shape and the mounting part is embedded and fixed in the manhole wall, the hole for attaching the foothold hardware is not provided. They have to be drilled individually into the manhole wall, requiring a lot of man-hours for installation, and it becomes very troublesome to replace the footholds when they become corroded.

Furthermore, if the foothold hardware is attached to a side wall different from the one along which the cable runs, the effective space within the manhole will be reduced accordingly. Therefore, from the viewpoint of space, it is desirable to attach the foothold hardware to one side wall along which the cable runs, but since one side wall has many holes as described above, it is necessary to install the foothold hardware attachment holes. Drilling new holes means that the holes for the brackets and the holes for the footholds are close to each other or partially overlap each other, so it is essentially necessary to make multiple footholds in a line vertically. It cannot be attached to a predetermined position, and there is also a problem in terms of strength.

In view of the above-mentioned problems, the present invention attempts to provide a manhole structure that makes it possible to easily perform installation and removal operations by using bracket holes pre-formed in the side wall along which the cable runs.

(Means for Solving the Problem) Therefore, the present invention provides a manhole wall with a plurality of mounting holes formed on one side wall for mounting cable rack brackets, and mounting holes formed on both sides of the footrest. The ends of the manhole were bent along the manhole wall, insertion holes were bored in both ends at locations corresponding to the mounting holes, and the both ends were fixed with bolts or the like that were screwed into the mounting holes. It is characterized by

In the present invention, the manhole wall to which the foothold hardware is attached is provided with a large number of cable rack bracket mounting holes in both vertical and horizontal directions in advance, and the fixing bolt insertion holes are provided in the bracket mounting holes. Form at corresponding positions to match.

The side surface of the mounting portion on the manhole wall side is configured to come into surface contact with the wall, so that rattling can be effectively prevented even during long-term use.

A female threaded pipe or fixing bolt is inserted into the hole in the manhole wall. A fixing bolt or a tightening nut is screwed into the pipe or the fixing bolt, respectively, so that the surface contacting portion of the mounting portion is fastened and fixed to the manhole wall.

To prevent corrosion, the surfaces of these fastening parts with threaded parts should be coated with FRP or ceramics, or the entire fastening part itself should be protected.
It is best to make it from FRP or ceramics.

(Function) When the manhole structure of the present invention is used in a manhole for power transmission lines, a female threaded pipe or bolt is fixed in advance in the hole on the manhole wall side, and a foothold is placed on the manhole wall to secure the mounting part. The insertion hole is positioned so as to fit with the female threaded pipe or bolt.
Next, the surface contact portion of the mounting portion is tightened with a bolt that is threaded into the female threaded pipe or a nut that is threaded into the bolt, thereby completing the work of fixing the foothold hardware.

On the other hand, the foothold hardware can be removed by loosening the bolt threaded into the female threaded pipe or the nut threaded into the bolt.

In this way, the manhole structure of the present invention allows for easy installation and removal work using the existing holes in the manhole wall, which eliminates the need to drill new holes for attaching foothold hardware. Become.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In Fig. 1, reference numeral 1 denotes a manhole installed in the middle of a conduit-type power transmission line, and on one side wall of the manhole, a large number of mounting holes 3 for cable rack brackets 2 are pre-formed at predetermined intervals in both the vertical and horizontal directions. . Power cables and communication cables (not shown) are installed between the brackets 2, which are hooked and fixed at necessary locations in the large number of holes 3. The mounting holes 3 to which the brackets 2 are not attached will be used when additional cables are installed in the future.

Brackets 2, 2 on the wall of manhole 1
A footrest 4 is fixed to the horizontal center position between the two using the mounting hole 3. This footrest hardware 4
As shown in FIG. 2, a light reflector 5 and a wavy finger hook 6 are provided on a foothold 7, and L-shaped attachment portions 8 are bent at both ends of the foothold 7. They are installed consecutively.

The distal end surface of the mounting portion 8 is a contact portion 9 that makes surface contact with the wall of the manhole 1. The mounting portion 8 and the foot 7 are entirely covered with synthetic resin, and an anti-slip pattern is formed on the outer surface of the foot 7, including at least the upper surface. An insertion hole 10 is formed in the mounting portion 8 at a location corresponding to the hole 3, and as shown in FIG. 3, a synthetic resin protective coating 11 is also formed on the inner surface of the insertion hole 10. A fixing bolt 12 is inserted into the insertion hole 10.

Reference numeral 13 in Fig. 3 is a bolt base fixed unrotatably to the wall of manhole 1, and the inner surface is made of FRP.
Alternatively, it is coated with ceramics and has a female thread.

Therefore, when installing this foothold hardware,
It is only necessary to hold the mounting part 8 so that the hole 10 of the mounting part 8 is aligned with the hole 3 of the wall of the manhole 1, and tighten the mounting part 8 through the washer 14 with the bolt 12 which is screwed into the female threaded part of the bolt base 13. In this case, the bolt 12 is attached to the FRP 12 as shown in FIG.
The one coated with (a) shall be used.

FIG. 5 shows another embodiment of the fastening means, in which a bolt 12' is inserted into the hole 3 in the wall of the manhole 1.
This is fitted into the hole 10 of the mounting portion 8 and tightened with a nut 15 via one or two washers 14. The bolt 12' has a taper pin 16 on the slotted side and is driven into the hole 3 and fixed.

FIG. 6 shows another example of the footrest according to the present invention, in which, unlike the previous embodiment, the tip of the mounting portion 8 is bent upward, and the fixing bolt insertion hole 10 is formed in the footrest 7. It is located above the height of
With this configuration, it becomes easier to rotate the bolt with a tool. Of course, the distal end of the mounting portion 8 may be bent downward, and the fixing bolt insertion hole 10 may be provided at a height below the footstep portion 7.

The present invention is not limited to the above embodiments. For example, the seventh
As shown in the figure, it is also conceivable that the open end side of the hole 3 is stepped, and a protrusion 17 that fits into the stepped portion is provided on the peripheral edge of the fixing bolt insertion hole 10 of the mounting portion 8.

(Effects of the invention) As described above, according to the invention, since the fastening parts can be rotated from inside the manhole by using the existing holes in the manhole wall, a special mounting hole for the foothold hardware can be newly created. Since the insertion hole of the foothold hardware is aligned with the mounting hole without the need to install a Since the number of holes does not increase, the strength of the manhole structure and the mounting strength of the footholds are not impaired.

Furthermore, since the foothold hardware is provided on the inner wall surface on the cable side, the effective space within the manhole is increased compared to the conventional structure provided on the inner wall surface on the side different from the cable.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an enlarged perspective view of the foothold hardware in Figure 1, Figure 3 is a sectional view showing the fastening part of the foothold hardware, and Figure 4 is
5 is a cross-sectional view showing another example of the fastening part of the foothold hardware of the present invention; FIG. 6 is a cross-sectional view showing the fastening part of the foothold hardware according to another embodiment of the present invention. The perspective view shown in FIG. 7 is a sectional view showing a modification of the fastening part of the footrest. 1... Manhole, 2... Cable rack bracket, 3... Mounting hole, 4... Foothold hardware, 7...
...foot section, 8...attachment section, 10...bolt insertion hole, 12...fixing bolt, 15...nut.

Claims (1)

[Scope of utility model registration request] A manhole wall has a plurality of mounting holes formed on one side wall for mounting cable rack brackets, and the ends of the mounting portions formed on both sides of the footrest are bent along the manhole wall. A manhole structure characterized in that insertion holes are bored at both ends at locations corresponding to the attachment holes, and the both ends are fixed with bolts or the like screwed into the attachment holes.