JPH0135123B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention provides a method for preventing expansion and contraction of cables due to temperature changes when installing power cables on bridges.
The present invention also relates to a cable expansion/contraction absorption device capable of absorbing expansion/contraction of a bridge.

When installing power cables on a long bridge, in order to prevent excessive stress from acting on the cables, it is necessary to give the cables a snake-like slack to absorb the expansion and contraction of the cables due to temperature changes. In addition, it is necessary to absorb the amount of expansion and contraction of the bridge without causing local deformation of the cables, even when the bridge expands and contracts due to temperature changes or loads caused by passing vehicles.

Conventionally, as a means for this purpose, as shown in FIG. 1, a mechanism is known in which a cable 1 is attached to various parts of a pantograph 2 in a vertical plane and supported in a vertical snake shape. In Fig. 1, 2a is the crossing part of the pantograph 2, 2b and 2c are the upper and lower connecting nodes of the pantograph 2, respectively, 2d is the fixed node of the pantograph 2 fixed to the bridge pier, and 3 is parallel to the bridge. The installed pedestal, 4 is pantograph 2
A roller 5 is a clamp that grips the cable 1. Then, when the bridge expands and contracts, cable 1
Due to this expansion and contraction, the movement of the bridge is added to the pantograph 2, causing the pantograph 2 to expand and contract, thereby evenly distributing the amount of expansion and contraction of the bridge to each part of the snake-shaped slack of the cable 1, and causing the pantograph 2 to expand and contract. This prevents large stress from being applied.

However, the above-mentioned conventional cable expansion/contraction absorption device uses a pantograph mechanism consisting of an organic combination of a large number of link rods, so the device configuration is complicated, and since the cable 1 is directly attached to the pantograph 2, it requires multiple cables. When installing cables with attached racks, it is necessary to install a large number of pantographs corresponding to the number of cables, which has the disadvantage that the entire device becomes extremely large.
For example, in the case of a bridge exclusively for trains, it may be difficult to secure a patrol passage for security purposes.

This invention was proposed to solve the above-mentioned conventional drawbacks, and the mechanism is not complicated and large, and even when multiple cables are installed along a bridge, it can be made compact with a good space factor. The purpose of this invention is to obtain an expansion/contraction absorbing device for cables attached to a bridge, which can be attached to a bridge in bulk.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 8.
This will be explained with reference to the figures.

In FIG. 2, numeral 10 indicates a pier, and the pier 10 is divided into parts with an expansion/contraction absorption allowance l, and one side is a fixed side bridge 11 fixed to the pier 10.
The other side is a movable bridge 12 that expands and contracts.

13 is a base frame provided on the side of the bridge along its longitudinal direction, and on the base frame 13 of the fixed side bridge 11, a plurality of movable support stands 14 are arranged at intervals in the bridge length direction. .

This movable support stand 14 has a plurality of cleats 16 for fixedly holding cables 15 fixedly held by, for example, horizontal horizontal frames 14a in three upper and lower stages, and a base part 14b.
It has wheels 14c and is movable along the length direction of the bridge on rails 17 provided on the base frame 13. A push rod 14d is fixed to the front part of the base part 14b of each movable support stand 14 (the right side or right side in FIG. 2 is referred to as the front or front, and the opposite is referred to as the rear or rear). An engaging piece 14 is provided at the tip of this push rod 14d.
e is fixed, while the base part 1 of the movable support base 14
An engagement tube 14f is fixed to the rear of the movable support base 14 on the rear side, and accommodates the engagement piece 14e of the movable support base 14 on the rear side with a certain amount of movement so as not to disengage the engagement tube 14f. A compression elastic member 14g made of a compression coil spring is housed, and each adjacent movable support base 14 is interconnected by a push rod 14d via the compression elastic member 14g.

Further, a drive push rod 18 for driving the movable support is fixed to a mounting base 12a fixed near the end of the movable side bridge 12, and this drive push rod 18 is
It is connected to the rear part of the base portion 14b of the rearmost movable support table 14.

The cleat 16 is composed of an upper member 16b and a lower member 16c forming three horizontally arranged holes 16a, as shown in the enlarged view of FIG.
The cable 15 passed through the upper member 16b
It is fixed to this cleat 16 by bolting it to the lower member 16c.

In addition, a cable 1 is connected between each movable support base 14.
An intermediate roller frame 19 is installed, which receives the cable 5 on the movable support base 14 at the same height as the cable height position by a roller 19a. In this embodiment, for example, four movable support stands 14 are provided as shown in FIG. 4, and the interval m between them is, for example, about 4.5 m. 20 is a fixed cable support fixed frame.

In the cable expansion/contraction absorption device described above, the cable 15 is fixedly held by the cleat 16 of the movable support base 14, and the cable 15 is fixedly held by the cleat 16 of the movable support base 14, and
As shown in FIG. 4, the cable is received in a horizontal plane and curved into a snake shape.

Then, due to thermal expansion of the bridge due to temperature changes,
Alternatively, if the moving side bridge 12 moves forward in the longitudinal direction of the bridge due to the weight of the passing vehicle, the drive push rod 18 fixed to the moving side bridge 12 moves forward and the rear end moves. Support stand 14
The movable support base 14 at the rear end is pushed forward by the push rod 14d, and the second movable support base 14 from the rear is pushed through the compression elastic member 14g.
is pushed forward, and the third and fourth movable support tables 14 are similarly pushed forward, thereby narrowing the intervals between the four subspans m between each movable support table 14. At that time, the cable 15 is fixedly held by each movable support base 14 and the cleat 16 of the cable support fixed frame 20, and is also supported by the intermediate roller frame 19 without restriction of movement in the horizontal plane. The amount of curvature (sag) of the cable 15 increases within each of the subspans m, thus absorbing the elongation of the cable due to the movement of the bridge.

To explain the above behavior in more detail,
If the compressive elastic member 14f were not present, the distance between the movable supports 14 would gradually narrow from the rear subspan, but in the configuration of the present invention, the movable supports 14 are connected to each other via the compressive elastic member 14g. Therefore, when the span interval on the rear side narrows due to the compression of the compression elastic member 14g, a thrust is applied to the front movable support base 14 due to the reaction force of the compression elastic member 14g. As a result, the movable supports 14 move simultaneously while narrowing the distance between them, and the elongation of the cables caused by the movement of the movable bridge 12 is distributed within each span.
In other words, if the compressive elastic member 14g does not exist, when the movable bridge 12 repeatedly moves back and forth within a relatively small movement range, the cable 15 will always be deflected locally only within the rear span. However, if the compression elastic member 14g is present, such an inconvenience will not occur.

Also, when the movable bridge 12 moves backward (to the left in Fig. 2), contrary to the above operation,
The drive push rod 18 pulls the rearmost movable support 14, and each movable support 14 moves backward by the reaction force of the compression elastic member 14f of the front movable support 14, and each subspan distance is increased. The cable 15 can be easily expanded and contracted.

FIG. 6 shows another embodiment of the means for connecting movable support stands, and this movable support stand 21 has push rods 21d whose axes coincide with each other at the front and rear parts of the base part 21b. , and adjacent movable support bases 2
It has a compressive elastic member 21g that is fitted onto the opposing push rods 21d and connects the movable support base 21 with a movement distance h between the push rods 21d.

In this case as well, the moving side bridge 1
2 is transmitted to each movable support base 21 via each compression elastic member 21g, and the amount of expansion and contraction of the cable accompanying the movement of the movable bridge 12 is distributed within each subspan. In this embodiment, since the minimum distance between the movable supports 21 is accurately defined by the travel distance h between the push rods 21d, there is no problem that the absorption distance for one subspan becomes narrower than the set value. definitely avoided.

FIG. 7 shows another embodiment of the cable fixing and holding means, that is, the cleat.
A is formed of three members: an upper member 22b, a lower member 22c, and an intermediate spacer member 22d, and the cables 15 are laid in a stacked manner. According to this cleat 22, the cables 15 can be laid in a compact manner with a narrower width.

FIG. 8 shows another embodiment of a movable support, which is applied when laying the cable 15 in a trough. That is, this drive support stand 23
In this example, wheels 23c are provided on a trough-shaped frame 23a, and a cleat 24 is attached within the trough-shaped frame 23a. In addition, 25 is a vertical metal fitting fixed to the side of the bridge, 26 is a trough receiving metal piece fixed to this vertical metal fitting 25, and 27 is a rail. This movable support stand 23 is equipped with a push rod 23d and a compression elastic member (not shown), etc., as in the embodiment shown in FIG. do.

In the embodiment, the driving push rod 18 and the movable support base 14 on the rear side are directly connected, but this connection is made via a compression elastic member, similar to the means for connecting the movable support bases 14 to each other. You can go. In this case, expansion and contraction of the cable is also accommodated in the sub-span of the drive push rod 18 portion.

Furthermore, in the embodiment, the movable support stand 14 is provided beside the fixed side bridge 11, and the drive push rod 18 for driving the movable support stand 14 is fixed beside the movable side bridge 12. Conversely, even if the movable support stand 14 is provided on the movable side bridge 12 and the driving push rod 18 is fixed on the fixed side bridge 11, the expansion and contraction of the cable can be absorbed by the same effect.

Further, in the embodiment, the cable 15 is laid in a curved manner in a snake shape in a horizontal plane, but it may be laid curved in a snake shape in a vertical plane. Of course, in this case, the intermediate roller frame 19 is unnecessary.

As explained above, according to the present invention, when a long bridge expands and contracts, the amount of movement of the cables due to the expansion and contraction of the bridge can be absorbed without creating excessive stress on the cables. The cable is fixedly held on a plurality of movable supports, and these movable supports are driven by a driving push rod and a push rod via a compression elastic member attached to each movable support, which is different from the conventional mechanism. Compared to a pantograph mechanism, the structure is simpler and the weight of the entire device is lighter, and by fixing and supporting multiple cables at once on a movable support base, it can be used in narrow spaces in the width direction of the bridge. It is possible to lay multiple cables together in a compact manner with good space efficiency. As mentioned above, by interposing the compressive elastic member, the amount of expansion and contraction of the cable due to the movement of the moving side bridge can be reliably distributed within each subspan, and therefore the generation of local deflection of the cable is effective. is prevented.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the mechanism of a conventional cable expansion/contraction absorption device attached to a bridge, Fig. 2 and the following show an embodiment of the present invention, Fig. 2 is a side view, and Fig. 3 is a front view thereof. , FIG. 4 is a schematic plan view, FIG. 5 is an enlarged view of the cleat, FIG. 6 is a side view showing another embodiment of the coupling mechanism between the movable support bases, and FIG. 7 is a diagram of another embodiment of the cleat. , FIG. 8 is a front view showing another embodiment of the movable support base. 11... Fixed side bridge, 12... Moving side bridge, 1
4, 21, 23...Movable support stand, 14d, 21
d, 23d...Push rod, 14e...Engagement piece, 14
f... Engagement cylinder, 14g, 21g... Compression elastic member, 15... Cable, 16, 22, 24... Cleat, 18... Drive push rod.

Claims (1)

[Claims] 1 A plurality of movable support stands 21 and 23 fixedly holding the cable 15 are placed on either the fixed side bridge 11 or the movable side bridge 12 at intervals in the bridge length direction, and are movable in the bridge length direction. At the same time, each movable support is provided with compressive elastic members 14g and 21 to connect adjacent movable supports.
Push rods 14d, 21d, 23 connected via g
d, and at the end of the movable side bridge or the fixed side bridge where no movable support is installed, there is a cable support fixed frame 20 that fixedly holds the cable.
At the same time, a drive push rod 18 for driving a movable support base is fixed, and this drive push rod is connected to a movable support base located adjacent to this, and the cable is connected in a snake shape by the plurality of movable support bases. A device for absorbing expansion and contraction of cables attached to a bridge, characterized by being laid in a curved manner.