JP2933175B2 - Cable anchoring device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a cable anchoring device used to prevent a cable from moving due to a so-called waving phenomenon or a sliding phenomenon on a slope.

(Prior Art) When there is a road or a railroad on which a cable is buried, there is a phenomenon that the cable is drawn in the same direction as a vehicle runs. This phenomenon is called a wave phenomenon.
If the cable is drawn into the pipeline due to such a wave-driving phenomenon, a problem such as an offset problem or a core deviation may occur, which may adversely affect the line. In addition, there is a possibility that the cable laid on the sloping ground may slide down due to gravity. Conventionally, in order to prevent these, a cable anchoring device is attached to the mouth of the manhole to prevent the cable from being pulled in. Further, the cable anchoring device is adapted to follow the thermal contraction of the cable.

The principle of the cable anchoring device will be described with reference to FIG.

As shown in the drawing, the cable 1 is drawn into the conduit 3, the support bolt 4 is inserted between the flange portion 6 of the tubular main body and the support fitting, and the retaining spring 2 is interposed in this.

In the figure, when the force which the cable 1 is drawn into the conduit 3 by surfing phenomenon or sliding the F _1, the force
Using the anchor spring 2 can absorb F _1, cable 1 by balancing the force F ₂ and F ₁ of the anchor spring 2
Is retained so as not to be drawn into the pipeline 3.

(Problems to be Solved by the Invention) In the case of the above-described conventional cable anchoring device, the length of the stud bolt 4 through which the spring is inserted is determined by the stroke R of the anchoring spring 2 to be anchored and the stroke S by extension due to the heat cycle. Must be added to the length. Therefore, in the structure of the conventional cable anchoring device, the entire stroke of the anchoring spring 2 is L = R + S, and an extremely large stroke is required.

In addition, when the stud bolt 4 is attached to the retaining spring 2, the force is increased in the direction in which the cable 1 protrudes from the pipe line 3 because the extension spring contracts the stroke S. Therefore, this point must be taken into consideration in the design, and the design is complicated.

Further, when the anchoring device is attached to the mouth of the conduit 3, the stroke S due to extension is tightened with the nut 5, and
, It was very difficult to perform the work in a narrow manhole.

By the way, there is no stroke S due to extension,
When the anchoring spring 2 having a short stroke as a whole is designed and mounted on a cable anchoring device, the following problems occur.

More specifically, FIG. 4 shows a more detailed spring mounting structure. The retaining spring 2 inserted through the stud bolt 4 is provided between the flange portion 6 of the cylindrical main body and the supporting metal member 7 arranged oppositely. , 8 are installed through. For this reason, in the conventional structure, when the retaining spring 2 is extended by the heat cycle and returns to the original set position, the retaining spring 2 comes off the guide cylinders 8 and 8, and the retaining force at the time of design is obtained. Unavailable situation occurs. For this reason, in the past, it was necessary to use the retaining spring 2 having a large stroke as a whole having a stroke S due to extension.

FIG. 4 (A) shows a state in which the cable anchoring device is set in a pipeline, FIG. 4 (B) shows a state in which the cable has been extended by a heat cycle, and FIG. 4 (C).
Indicates a state in which it has returned to the processing set position from the extended state in FIG.

The present invention has been made in order to solve the above-described problems, and uses a retention spring that does not have an extension stroke, so that a force in a direction in which a cable jumps out of a pipeline at the time of setting does not act, It is an object of the present invention to provide a cable anchoring device that can be easily mounted even in a narrow manhole and that has been downsized.

(Means for Solving the Problems) The present invention includes a support fitting fixed to a fixed position and through which a cable whose movement is to be restricted is passed, and a flange fixed to the cable and facing the support fitting. A tubular main body, a support bolt extending from the support fitting through the through hole of the flange portion, and a long tube movably mounted on the support bolt through the through hole of the flange portion. A body portion, a nut screwed to a tip of the support bolt, and a nut for restricting the movement by bringing the flange portion into contact with the cable when the tubular main body moves in a direction away from the support fitting together with the cable; and A retaining coil spring, one end of which abuts on the support bolt and is mounted on the support bolt in an incompressible manner, and an end provided integrally with an end of the long cylindrical body facing the support bracket, Coil spring And a guide tube which is pressed by the flange portion when the cable moves in the opposite direction to apply the compressive force of the coil spring for retention.

(Operation) Since the cable anchoring device of the present invention uses the anchoring spring having no stroke for extending the cable, no force acts in the direction in which the cable jumps out of the pipeline at the time of setting. In addition, since the retaining spring does not need to be contracted at the time of setting, the mounting operation becomes easy even in a narrow manhole.

Furthermore, when the cable extends, the flange portion of the tubular main body of the cable retaining device only slides outward on the long tubular portion of one guide cylinder, and the length of the retaining spring is set at the time of setting. Since the length is the same as that of the length, the retaining spring does not come off from the guide cylinder arranged oppositely.

Example An example of the present invention will be described below with reference to the drawings.

1 is an overall view of a cable anchoring device of the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a right side view.

In the figure, a cable anchoring device 10 has a tubular main body, and in the example of the figure, upper and lower divided tubular main bodies 11, 12 which are fastened by bolts 13, 14. ing.
The upper cylindrical body 12 has a shape in which the upper right half shown in the drawing is cut off. On this semi-mounting surface, that is, on the lower cylindrical main body 11, two upper lids 15 constituting a cleat are attached.

The upper lid 15 has a pair of upright cylindrical body portions 16, and a coil spring 17 is inserted into each of the upright cylindrical body portions 16, and a bolt
It is fixed to the base 11a of the lower cylindrical main body 11 by 18.

Between the flange portions 11b and 12a of the upper and lower cylindrical bodies 11 and 12 which are overlapped with each other and the support fitting 19 which is arranged in opposition to the flange portions 11b and 12a, a total of four springs 20 for upward and downward parallel arrangement are provided. Is attached. That is, the retaining spring 20 is connected to the flange 11
It is attached to a support bolt, for example, a stud bolt 21 inserted between b, 12a and the support fitting 19. FIG. 2 illustrates the structure of this portion in more detail.

In the drawing, one end 21a of the stud bolt 21 is screwed to the support fitting 19. Then, guide cylinders 22 and 23 for supporting the retaining springs 20 are arranged between the flange portion 11b (12a) of the cylindrical main body 11 (12) shown in FIG. . One of the guide cylinders 23 has an elongated cylinder portion 24 extending in the axial direction on the side opposite to the side supporting the retaining spring 20. The length of the long cylindrical body portion 24 is designed in consideration of the distance that the flange portion 11b (12a) slides outward due to the cable extension, that is, the stroke S of the cable extension. The flange 11b (12a) is inserted through the bush 25 around the outer periphery of the long cylindrical body 24. Bush 25
It is fixed to the flange portion 11b (12a) by a washer 26 also serving as a nut.

A nut 27 is screwed onto the protruding end 21a of the stud bolt 21 inserted into the long cylindrical body 24, and the nut 27
By tightening, the guide cylinder 23 moves rightward in the figure to compress the retaining spring 20.

Next, the operation of the cable anchoring device 10 having the above configuration will be described with reference to FIGS. 2 (A) to 2 (D).

First, FIG. 2A shows a state in which the cable anchoring device 10 is set at a predetermined position in a pipeline. In this state,
The long cylindrical body portion 24 of the guide tube 23 projects leftward from the flange portion 11b (12a) by the stroke S at which the cable extends.

Next, when the cable extends due to the heat cycle, the flange portion 11b (12a) slides on the long tubular portion 24 and moves to the left as shown in the drawing (B). In this case, since the position of the retaining spring 20 is regulated by the guide cylinder 23, the retaining spring 20 does not extend and remains the same as the length when set.

FIG. 7C shows a state where the flange portion 11b (12a) has returned to the initial set position.

Next, FIG. 3D shows a state where the cable is drawn into the pipeline, the flange portion 11b (12a) moves rightward in the drawing, and the guide cylinder 23 compresses the retaining spring 20 for the first time. Will do.

As described above, in the cable anchoring device 10 of the present invention, it is sufficient to consider only the stroke R for obtaining the cable anchoring force without considering the cable extension stroke S as the entire length of the anchoring spring 20. , Its overall length is reduced.

Next, a specific design example of the above-described retaining spring 20 will be described in comparison with a conventional retaining spring.

For example, it is assumed that a retention force of 20 kgf is required, the outer diameter of the retention spring is 30 to 40 mmφ, the extension stroke S is 50 mm, and the retracted stroke R is 50 mm.

 First, the design of the conventional retaining spring is as follows.

That is, since the stall S that has been extended has to be considered in the related art, in addition to the originally required stroke R, S +
R = 50 + 50 = A pulling spring must be designed so that a pulling force of 20 kgf is obtained when it is reduced by 100 mm.

 In this case, the spring constant K is represented by the following equation.

K = Yield force / Total stroke = 20/100 = 0.2 kgf / mm (1) By the way, the following formula (2) is generally used for spring design.

Spring constant K = Gd ⁴ / 8nD ³ (2) The symbols in the equation (2) are as follows.

G: Elasticity coefficient (using 7000 kg / mm ² ), d: Spring wire diameter (mmφ), D: Coil spring average diameter (mm), n: Effective number of turns of the coil spring, where n is the effective number of turns of the coil spring If the length is too small, it is not possible to design a product with a long stroke such as a total length of 100 mm.

As a result of designing as described above, K = 0.2 kgf / m as described above.
m, d = 4 mmφ, D = 30 mmφ, n = 41.5, and the total number of turns = 43.5. The contact length was 174 mm, and when the total stroke was 100 mm, the natural length was 274 mm.

On the other hand, the design example of the retaining spring in the present invention is as follows.

In the present invention, since the extension stroke S does not need to be considered, only the original stroke R = 50 mm needs to be considered in designing the retaining spring.

Therefore, from the above equation (1), the spring constant K is K = 20/5
0 = 0.4 kgf / mm. Further, when each is calculated using the above equation (2), the following is obtained.

Since K = 0.4 kgf / mm as described above, d = 4 mmφ, D
= 30mmφ as before, n = 20.5, total number of turns = 22.
5 was obtained. The contact length is 90, and the total stroke is 5
When 0mm was secured, the natural length was 140mm.

The above is summarized as shown in FIG. In this figure, the set length indicates the total length of the anchoring spring when the cable anchoring device is set in the pipeline.

(Effects of the Invention) Since the present invention is configured as described above, the following effects can be obtained.

(1) The cable anchoring device of the present invention uses an anchoring spring that does not have an extension stroke due to a heat cycle, so that no force acts in the direction in which the cable jumps out at the time of setting to a pipeline, and installation work is performed. Becomes easier.

(2) Since the anchoring spring does not need to be compressed at the time of setting, it is easy to mount the cable anchoring device in a narrow manhole.

(3) The design of the retaining spring does not need to consider the stroke at the time of extension, but only the retracting stroke for obtaining the retaining force. Therefore, the total length of the retaining spring can be shortened. This can contribute to downsizing of the entire cable anchoring device.

[Brief description of the drawings]

FIG. 1 is an overall view showing an embodiment of a cable anchoring device according to the present invention, wherein FIG. 1 (A) is a plan view thereof, FIG. 1 (B) is a front view thereof, and FIG. FIG. 2 (A),
(B), (C) and (D) are cross-sectional views for explaining the operation of the anchoring spring and the guide tube in the cable anchoring device, FIG. 3 is a schematic configuration diagram showing a conventional cable anchoring device, and FIG. FIGS. (A), (B) and (C) are cross-sectional views for explaining the operation of the anchoring spring and the guide tube in the conventional cable anchoring device, and FIG. 5 is a comparative illustration of the conventional product and the product of the present invention. FIG. 10 ... Cable anchoring device, 11,12 ... Cylindrical body, 19 ... Support bracket, 20 ... Anchoring spring, 21 ... Support bolt, 22,23 ... Guide cylinder, 24 ... Long cylindrical shape Part, 27 ... nut.

Claims (1)

(57) [Claims] A supporting member fixed to a fixed position and through which a cable whose movement is to be regulated is passed; a cylindrical body fixed to the cable and having a flange facing the supporting member; and the supporting member. A support bolt extending through the through hole of the flange portion from a long cylindrical body portion movably mounted on the support bolt through the through hole of the flange portion; and A nut that is screwed to the tip and moves the cylindrical body together with the cable in a direction away from the support fitting, and a nut that restricts the movement by contacting the flange portion, and one end of the nut that contacts the support fitting. A retaining coil spring that is mounted on the support bolt in an uncompressed state, and is integrally provided at an end of the long cylindrical body portion facing the support bracket, and supports the other end of the retaining coil spring. With, before Cable anchor apparatus, characterized in that it comprises a guide tube which is pressed against the flange portion during movement in the opposite direction of the cable imparts a compressive force of the anchor coil spring.