JPS5915219Y2 - Cable expansion and contraction device - Google Patents

Description

[Detailed explanation of the invention] This invention is a cable expansion/contraction absorbing device, and in particular, the cable itself is designed not only to expand and contract due to the effects of expansion and contraction of the bridge due to temperature changes, etc., but also to the cable itself due to load fluctuations and seasonal fluctuations. This invention relates to a device that also absorbs thermal expansion and contraction.

Recently, there have been an increasing number of cases in which electric power cables are installed on bridges due to site conditions and other reasons.

In this case, the spacing between the discontinuous parts of the bridge girder changes due to changes in temperature, expansion and contraction of the bridge due to the passage of automobiles, etc.

For this reason, the attached cables expand and contract at discontinuous portions of the bridge girder, following changes in their spacing.

Such cable expansion and contraction is absorbed by providing slack sections called offsets in the cables at discontinuous portions of the bridge girder.

As an example, the distance between discontinuous parts of a bridge girder may expand or contract by as much as 1000 mm due to the above reasons.

In order to absorb the expansion and contraction of the cable that follows this degree of expansion and contraction, it is necessary to form a large slack part called an offset in the cable with a width F of 4000 mm and a length 2L of approximately 11000 mm, taking into account the repeated fatigue of the cable. There is.

Generally, such large slack sections are provided between discontinuous ends of bridges to prevent the bending radius from becoming locally small when the cable deforms due to expansion and contraction absorption, and to maintain the designed shape over a long period of time. A pantograph is provided in combination at the slack portion so that the cable always deforms uniformly depending on the amount of expansion and contraction of the cable.

Fig. 1 shows a state in which a conventional pantograph is installed in a slack part having the above dimensions. In the figure, 1 is a slack part formed in the cable and has a width F" 40
00 mm, length 2 L = 11000 mm, length 2 L
It forms a slight curvature in the width direction symmetrically to the perpendicular bisector of.

C is the apex of the slack part, A and E are the curved end points of the slack part, and the cable is laid straight at points A and E, with A being the moving point and E being the fixed point.

Let B and D be the respective midpoints between the moving point A and the vertex C1, the vertex C, and the fixed point E.

2 is a pantograph which, as is well known, can be expanded and contracted by combining two arm pieces; one end of these arm pieces is connected to each other with a pin at connection point C, and the other ends are designated as points a and e, respectively.
Let point a be a moving point and point e be a fixed point.

Let d be the midpoint between moving point a, vertex C1, vertex C, and fixed point e.

3 is the moving end of the central girder of the bridge to which the cable is attached, 4 is the fixed end of the land side girder, point A of the slack part 1 and point a of the pantograph 2 are the moving end 3, and point E of the slack part 1. Point e of the pantograph 2 is fixed to the fixed end 4, respectively, and the slack portion 1 and the pantograph 2 are provided between the movable end 3 and the fixed end 4, which are opposite ends.

A pantograph 2 in which the movable end 3 is extended and fixed thereto.
The moving point a is M” 1000 in the direction of the fixed end 4.
If it moves by mm, the pantograph 2 follows this movement and deforms as shown by the dotted line 2', and each point a-d becomes a'~
Move to d', a, a/, b-, b', (-)C', d
, d' in the four directions of the fixed end are M (=1000 mm) 'hM (=7
50mm), HM (=500mm), 3AM (=
250 mm), (where M is the amount of movement of the moving end 3 in the direction of the moving end 4), the movement amount of point e is O, and the movement amount in the direction perpendicular to the movement direction is 0 and %2N, respectively.
(=197), N (=394), )/2N (=19
7), the amount of movement of point e is O (where N is the amount of movement of vertex C, which is determined by geometric calculation).

). In this case, the slack part 1 is deformed as shown by the dotted line 1', and each point of A-D moves to A' to D', but the slack part 1 is constructed by linearly connecting the curves ABC and CDE. Since it is considered to have the same configuration as the pantograph structure that was created, A-, A', B-, B', c, c', D→D'
The amount of movement in the direction of the fixed end 4 and the amount of movement in the direction perpendicular to this movement are respectively equal to the amount of movement of each point a to d on the pantograph 2.

Therefore, each point a to e on the pantograph 2 and each point A to E on the slack part 1 are respectively rotatably engaged with each other by connecting members and pin connections, thereby expanding and contracting the bridge, that is, the bridge of the pantograph 2. This allows the deformation of the slack portion 1 to always reliably follow the deformation due to expansion and contraction in the expansion and contraction direction.

In the above method, in order to match the increase in the width F of the slack portion 1 with the increase in the width H of the pantograph 2, the apex C of the pantograph 2 is set at HF (in the illustrated example, H-F
= 6465 mm -4000mm = 2465
mm) protrudes from the apex C of the slack portion, which is disadvantageous when installing cables in bridges where there are many space constraints.

In order to eliminate the above-mentioned drawbacks, a method of combining a pan graph and a cable slack portion as shown in FIG. 2 is known.

In the figure, the same parts as in FIG. 1 are designated by the same reference numerals.

In the figure, 1 is a slack part which has the same external dimensions as in Figure 1, and 21 is a width H equal to the width F of the slack part 1.
This is a trapezoidal pantograph which is configured to be extendable and retractable by combining a plurality of well-known arm pieces, which are combined into a slack part 1.

Center C of arm piece I forming the top side of trapezoidal pantograph 210
The apex C of the slack part 1 is rigidly connected to the arm piece II, and the arm pieces II forming the sides are connected to the end of the arm piece I on the movable end 3 side shown in FIG. 1 and the slack part 1, respectively. and the end of the arm I on the side of the fixed end 4 shown in FIG.

Curved end point A of slack part 1. E is the curved end point A of slack part 1
, E and the intersection point a1. with arm pieces II and III.
e1 and end point A of slack portion 1.

The bottom arm pieces V, which are formed by connecting E with pin connections, are connected to the ends a and e of bottom arm pieces VI, respectively, with rigid connections.

Furthermore, parallel to arm piece II, one end is pin-coupled to arm piece III and arm piece ■ at the joining point of arm piece I and arm piece III, and extends in a straight line, so that the end points A and E of slack portion 1 are An arm piece IV is provided whose other end is the intersection a2 with the connecting straight line.

By providing arm piece IV, arm piece I, II, I
V and point a1. a2 is shaped like a parallelogram, and the arm piece I is always a straight line a1. Since it remains parallel to a2, it is possible for the pantograph to maintain its trapezoidal shape.

Each point a, a1. of the pantograph 21. A2 is fixed to the moving end 3 as a moving point, and point e is fixed to the fixed end 4 as a fixed point.

Since the pantograph 21 is configured to be combined with the slack part 1 as described above, the lengths between the midpoint C of the arm piece I and the connection points of the arm pieces II and III on the arm piece I are equal. Of course, it is geometrically clear that this length is equal to the length between points a, a1 and e, 01, and that Z=
It was set to 972 mm.

Further, in this case, the projected length of the slack portions of arm pieces II, III, and IV onto the straight line connecting the end points A and E is W = 3557 mm, as shown in FIG. 2.

The pantograph 21 is combined with the slack portion 1 as described above and is provided between the movable end 3 and the fixed end 4.

The moving end 3 extends to a moving point a of the pantograph 21,
a1. a2 follows this and moves M in the direction of the fixed end 4.
(= 1000 mm), the slack portion 1 and the pantograph 21 will each move 1' as indicated by the dotted line.

21', and as explained in the previous example, each point A-D of the slack part 1 moves from A' to D', and the amount of movement in the four directions of the fixed end and the angle perpendicular to this direction of movement are The amount of movement in each direction is a of each point a to d of the pantograph 21.
Equal to the corresponding movement amount from ' to d', the lid edge numbers are M (= 1000 mm) and V4M (= 750 mm), respectively.
mm), AM (=500 mm), )/4M (=
250 mm) point e1, 0 at E, and '%t
N (= 192 mm), N (= 394 mm
), 'A N (= 192 mm), (N is the direction of movement of each point between the apex C of the slack part 1 and the pantograph 21 in the direction of the fixed end 4 of the arm piece (■) and the pantograph 21. (obtained geometrically by the amount of movement in the perpendicular direction), and therefore each point a of the pantograph 21
The movement of each point A to D of the slack portion 1 combined with this pantograph 21 always reliably follows the movement of -d.

According to this method, the pantograph 21 does not protrude from the apex C of the slack portion 1, so it is extremely advantageous in terms of space, and the moving points a, a1. a2
Since the fixed points e and e1 are fixed to the movable end 3 and the fixed end 4, respectively, the pantograph 21 and the slack portion 1 combined therewith reliably follow the expansion and contraction of the bridge and absorb the expansion and contraction of the cable. However, in reality, the cables C1 and C2 that are continuous with the slack part 1 also carry the transmission current (
Thermal expansion and contraction occurs due to changes in temperature due to changes in the load (load) and seasonal changes.
The moving point A and the fixed point E of the pantograph 21 extend, but since the points A and E are fixed to the moving end 3 and the fixed end 4 via points a and e of the pantograph 21, respectively, the heat The disadvantage is that expansion and contraction are restricted at points A and E and cannot be absorbed.

In order to absorb such expansion and contraction, pantograph 21
moving points a, a1. It is necessary to leave a2 and fixed points e and e1 free without fixing them to the moving end 3 and the fixed end 4.

However, if each of the above points is left free as described above, the bottom arm of pantograph 21 ■.

The pantograph 21 does not necessarily operate with VI and the moving point a2 always being held on the same straight line, and as the deformation cycle due to expansion and contraction is repeated, there is a high possibility that the pantograph 21 will deviate from the above-mentioned straight line.

For this reason, there is a drawback that it is difficult to always uniformly deform the slack portion 1 following the expansion and contraction of the moving end 3.

This idea can eliminate the drawbacks of sloping cables, can absorb not only the expansion and contraction of the bridge of the cable attached to the bridge, but also the thermal expansion and contraction of the cable itself, and is advantageous in terms of space. Its purpose is to provide a stretchable absorbent device.

The gist of this invention lies in the structure of the cable expansion/contraction absorbing device described in the claims of the utility model registration above.

This invention will be explained in detail below with reference to the drawings showing the embodiments thereof.

In FIG. 3, the same parts as in FIG. 2 are designated by the same reference numerals.

In the figure, reference numerals 22 indicate moving points a, a1, . A2 is not fixed to the movable end 3, but connected by a single arm piece, and arm pieces II and IV are rotatably connected with pins at a1 and a2, respectively, to form a bottom arm piece V'. , and the bottom arm pieces V' and VI' are trapezoidal pantographs composed of the bottom arm pieces VI' in which the fixed ends e and e1 of the bottom arm pieces VI in the pantograph 21 are not fixed to the fixed end 4 and are free. are arranged so as to form a straight line, and these bottom arm pieces V',
Opposite ends of VI' are connected by a fitting part 5 that is slidably fitted so that bottom arm pieces V' and VI' always move in a straight line as the pantograph 22 expands and contracts. Curved end points A and E of the slack portion 1 in FIG. 2 are respectively locked to points a and e at the free ends of the pieces V' and VI' by pin connections, respectively, and the movable end 3 in FIG. and the fixed end 4.

Also, the bottom arm piece V' and point a1. Since arm pieces I, II, IV and bottom arm piece V' form a parallelogram because they are pin-connected to a2, arm piece I always remains parallel to bottom arm piece V', so the pantograph can maintain its trapezoidal shape.

The length of the above fitting is determined by taking into consideration the amount of expansion and contraction of the cable, and the length of the bottom arm pieces V' and VI' that move following the expansion and contraction of the cable.
The opposing ends of the bottom arm pieces V' and VI', which are set to allow movement of the above-mentioned fitted state, are not limited to those that are slidably fitted and connected. , the object of the invention is achieved even if the bottom arm pieces V', VI' are connected by a telescopic joint which allows them to move respectively forming a straight line at all times.

In this case, the extendable amount of the telescopic joint must be sufficient to maintain the connected state of the bottom arm pieces V' and IV' against the respective movement distances of the bottom arm pieces V' and IV' following the expansion and contraction of the cable. It goes without saying that this is not the case.

Note that 6 is a pin that rotatably connects each arm piece.

Since this device has an inclined configuration, the curved end points A and E of the slack portion 1 shown in FIG.
Point a of bottom arm piece V' of 2, point e of bottom arm piece ■', apex C of slack part 1 to midpoint C of arm piece ■, and midpoints B and D of slack part 1. If the pantograph 22 and the slack part 1 are combined with the pantograph 22 by rotatably locking them at the midpoints s and d of the arm pieces II and III, respectively, the shape of the slack part 1 will always be maintained as designed. In addition, since the pantograph 22 is not fixed to the movable end 3 and the fixed end 4, it deforms following the thermal expansion and contraction of the cable itself and the expansion and contraction of the bridge, and the bottom arm pieces V' and VI' are always Since the opposing ends are slidably connected to each other so as to form a straight line and move, each point a, a1, . a2. b, C9d, e1. The amount of movement of each e is always maintained uniformly, so the above point a
The shape of the slack portion 1 connected to -e can always be uniformly deformed to absorb the repeated expansion and contraction of the cable over a long period of time.

Another embodiment of the present invention is shown in FIG.

In FIG. 4, the same parts as in FIG. 2 are designated by the same reference numerals.

In the figure, reference numerals 22 indicate moving points a, a1, . a2
is not fixed to the movable end 3, but is connected by a single arm piece with free binding, and arm piece II is attached at al and a2.

III are rotatably connected with pins to form a bottom arm piece V, and the fixed ends e and e1 of the bottom arm piece VI in the pantograph 21 are not fixed to the fixed end 4 and are free. The pantograph 22 is a trapezoidal pantograph configured with a bottom arm piece V', IV, and a rail fixed to the movable end 3 and the fixed end 4 so as to form a straight line in the cable installation direction. Alternatively, the cards 5 and 5' are slidably accommodated in groove-shaped cards 5 and 5', respectively, and are provided between the movable end 3 and the fixed end 4 in combination with the slack portion 1.

Note that 6 is a pin that rotatably connects the arm pieces.

Since this device has an inclined configuration, the curved end points A and E of the slack portion 1 shown in FIG.
The middle point B of the slack part 1 is rigidly connected to the point a of the bottom arm piece V' of 2, and to the point e of the bottom arm piece VI', and the apex C of the slack part 1 is rigidly connected to the middle point C of the arm piece I. , D are arms II and I, respectively.
If the pantograph 22 and the slack part 1 are combined by being rotatably locked at the midpoints s and d of II by pin connections, the shape of the slack part 1 will not only always be maintained as designed, but also the pantograph 22 is not fixed to the movable end 3 and the fixed end 4, so it deforms following the thermal expansion and contraction of the cable itself and the expansion and contraction of the bridge, and the bottom arm piece V'
, VI' are guided by the guides 5 and 5', respectively, and always slide while forming the same straight line, so the pantograph 2
2 each point a, a1. a2. The amount of movement of each of b, C5d, and e1゜e is always maintained uniformly, so the shape of the slack portion 1 connected to the above points a-e is always uniform even when the cable is repeatedly expanded and contracted over a long period of time. It can be deformed to absorb the expansion and contraction.

This idea has a diagonal structure and function, so if you follow this idea, it will be a simple structure, and it will not only be able to withstand the expansion and contraction of the cable attached to the bridge due to the repeated expansion and contraction of the bridge, but also the repeated thermal expansion and contraction of the cable itself over a long period of time. Since the deformation of the shape of the slack portion can be uniformly regulated and followed, and the expansion and contraction can be absorbed, cable accidents can be prevented from occurring, which has a great practical effect.

[Brief explanation of the drawing]

Figure 1 is a plan view for explaining the combination of a conventional pantograph and a slack part in a cable attached to a bridge; Figure 2 is a plan view for explaining a combination of a trapezoidal pantograph and a slack part in a cable attached to a bridge; The figure shows a trapezoidal pantograph according to this invention which is assembled to a slack part of a cable attached to a bridge, and FIG. 4 shows another embodiment of the invention. 1...Slack part of cable, 22...
Trapezoidal punk graph, I, II, III, IV,
V', Vl'- - arm piece, 3... curved bridge girder moving end, 4
... Bridge girder fixed end, 5 ... Recessed fitting part, 6 ... Connection pin.

Claims (1)

[Scope of utility model registration request] The cable attached to the bridge is fixed to the slack part provided between the bridge telescoping end and the opposite bridge fixed end, and is combined with the bridge telescoping end and the fixed end. A plurality of fixing points to the moving end of the bridge of the trapezoidal pantograph provided in between are not fixed to the moving end and are free;
A bottom arm piece is formed by connecting the fixing points with one arm piece with a pin connection, and an arm piece forming a top side with this bottom arm piece, an arm piece forming a side side, and this side side. The parallel diagonal arm pieces form a parallelogram to maintain a trapezoidal shape, and the other bottom arm piece, which is formed by connecting the fixed point to the bridge fixed end with a pin connection, is connected to the fixed end. The two bottom arm pieces are arranged to form a straight line and to be freely slidable, so that the two bottom arm pieces of the trapezoidal pantograph have free ends of the two bottom arm pieces at the respective end points of the slack parts. The apex of the slack part is rigidly connected to the midpoint of the arm piece forming the top side, and the midpoint of each slack part is fixed to the midpoint of each of the two arm pieces forming the side edge. A cable expansion/contraction absorption device characterized in that each cable is rotatably locked by a pin connection.