JPS6122458Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a cable line laid in a trough.

When laying power cables in a tunnel, in the event that a fire occurs due to a cable ground fault, etc., this is to prevent the fire from spreading into the tunnel, and to prevent the fire from spreading to other power cables. In order to prevent the effects of fire, a sealed disaster prevention trough is sometimes installed inside the tunnel, and power cables are laid inside the disaster prevention trough.

In such a cable line laid in a trough, three-phase cables consisting of three cables are usually stacked in a triangular shape (so-called bale stacking) and laid in a horizontal snake shape.

However, in bulk bale stacking, the cables are brought into contact with each other, so the heat generated by the energized cables is transferred to each cable, which unavoidably reduces the heat dissipation of the entire cable. The disadvantage is that a decrease in current capacity is inevitable, and the snake deformation of each cable is restrained by other cables, so the snake deformability of each cable is impaired, and the snake deformation absorption effect of cable thermal expansion and contraction is reduced. There is a disadvantage that there is concern about a decline in

The in-trough cable line according to the present invention has a structure that can eliminate the above-mentioned disadvantages, and consists of a lower piece and an upper piece, and these two pieces are connected by a joiner in the longitudinal direction in the FRP trough. At predetermined intervals, support plates for cable slides located approximately in the middle of the height inside the trough are locked and fixed at both ends to the joiner, and one or three of the cables of the three-phase cable consisting of three cables are connected to the The cable is laid in a horizontal snake shape on the support plate for the cable slide, and the remaining two or one cable is laid in a horizontal snake shape on the inner bottom surface of the trough.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is an explanatory cross-sectional view taken along the line - in FIG.

In Figures 1 and 2, 1 is flame-retardant FRP
It is a disaster prevention trough made of
These lower piece 1a and upper piece 1
b are connected by H-type jointers 1c, 1c. Reference numeral 2 denotes cable slide support plates, which are attached at predetermined intervals in the longitudinal direction of the trough at intermediate positions within the trough.

Cable slide support plate 2 is provided with claws 21, 21 at both ends, and these claws 21, 21 are connected to the
It is locked and fixed to the mold joiner 1C. 3 is a shielding plate laid on the inner bottom of the trough, and spacer 3
1,... (which may be integrated with the shielding plate or separate from it). This shielding plate 3 is used to prevent the cable from being flooded in the event that water enters the trough 1, and it is desirable that the height h from the inner bottom of the trough to the shielding plate is 20 to 30 mm. . The above-mentioned shielding plate 3 is used to prevent trough destruction due to the action of the fuselage in the event of a cable short circuit, and to prevent cable insulating oil (in the case of an OF cable) that flows out in the event of a ground fault in the trough from accumulating around the cable. It also has an effect.

W is three cables A, B, C (for example, single-core OF
It is a three-phase cable consisting of three cable strips), and one phase cable A is laid in a sinusoidal horizontal snake shape on the cable slide support plates 2, 2... mentioned above, and the remaining two phase cables are laid on the cable slide support plates 2, 2... Nijo B,
C is installed in a horizontal snake shape of a sine wave on the shielding plate 3 on the inner bottom surface of the trough. The horizontal snake shape and dimensions of each of these cables A, B, and C are the same, and the center point of the sine wave of the horizontal snake is fixed to the inner bottom surface of the trough by a three-strip cleat 4.

For example, in this three-strip cleat, see Figure 3A.
As shown in FIG. 3B (partially sectional front view) and FIG. If cable 3
The strips A, B, and C are tied together with a nylon rope or the like 41, and the substrate 40 is fixed to the trough bottom wall through bolt insertion holes 42 with bolts.

In the above, the three cables are arranged in a triangular configuration so that there is no unbalance in impedance and heat dissipation. It is also possible to lay one cable on the shielding plate on the inner bottom of the trough and the remaining two cables on the cable slide support plate. Furthermore, non-magnetic materials with low core loss, such as FRP plates and stainless steel plates, are used for the cable slide support plates and shielding plates, and non-magnetic materials with low core loss, such as aluminum castings and FRP, are used for the cable cleats. A mold material etc. can be used. Further, as shown in Fig. 1, support plates 5, ... for installing water cooling pipes are attached to the upper part of the trough at predetermined intervals in the longitudinal direction of the trough with bolts 51, and cables for indirect cooling are mounted on these support plates. It is also possible to install water cooling pipes 6, 6.

The in-trough cable line according to the present invention has the configuration as described above, and since each phase cable of the three-phase cable is laid separately into one and two lines, contact between each phase cable can be eliminated. , the heat dissipation of the entire cable can be improved well, and since each of the three separated cable strips is given a horizontal snake shape as described above, each cable strip can be smoothly deformed into a snake without being constrained by each other. , it can ensure good absorption of snake deformation due to cable thermal expansion and contraction. Furthermore, both ends of the cable slide support plate are locked and fixed to the jointer, and since the jointer is used to fix the cable slide support plate, it is different from the case where bolts etc. are used for fixing.
The mechanical strength of the FRP trough and the sealed disaster prevention mechanism can be maintained sufficiently.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a cable line according to the present invention, FIG. 2 is a cross-sectional view taken from FIG. 1, and FIGS. 3A and 3B are parts showing an example of the cleat used in the present invention They are a sectional front view and a side view. In the figure, 1 is a trough, 2, . . . are cable slide support plates, and A, B, and C are cable strips.

Claims (1)

[Scope of utility model registration request] Cable slide support plates are provided at predetermined intervals in the longitudinal direction of the FRP trough, which consists of a lower piece and an upper piece, and which are joined together by a joiner, and are located approximately in the middle of the height inside the trough. Its both ends are locked and fixed to the joiner, one or two cables of the three-phase cable consisting of three cables are laid in a horizontal snake shape on the cable slide support plate, and the remaining two or one cable is laid out on the cable slide support plate. A cable line laid inside a trough characterized by being laid in a horizontal snake shape on the inside bottom of the trough.