JP4993288B2 - Impact force absorbing device and metal fitting used therefor - Google Patents

Description

  The present invention relates to an impact force absorbing device made of a loop-shaped wire and a metal fitting structure used therefor, which is effective when used for an impact absorbing net or an impact absorbing shelf against avalanches, falling rocks and the like.

A technique for absorbing the avalanche and falling rock impact with a net or a shelf and preventing the avalanche from proceeding or falling down below is well known.
As one of the means to absorb such avalanche and falling rock impacts, the wire is formed in a loop shape, and when the tensile force acts on the wire, the impact is caused by the frictional force between the wires in the overlapping part when the loop part is reduced in diameter. Techniques for absorbing force are also known.

However, in a wire manufactured using a plurality of wires, when the diameter of the loop portion becomes smaller than a predetermined value, plastic deformation occurs in the wire, and the wire strength rapidly decreases and breaks.
Therefore, Japanese Patent Application Laid-Open No. 2006-97274 discloses a technique in which stoppers are provided on both sides of the support member of the overlapping portion of the loop so that the loop diameter does not shrink below a predetermined diameter.

  However, in the support member described in the publication, when the two wires in the overlapping portion of the loop are sandwiched by one metal fitting, the two wires overlap each other, so the frictional force between the wires starts to slide. Since the frictional force suddenly decreases once it begins to slide against the static frictional force up to the point, not only does the amount of shock absorption decrease, but there is also a variation in the contact between the wires. The amount of absorption itself was unstable.

JP 2006-97274 A

In view of the technical problems inherent in the background art described above, an object of the present invention is to provide an impact force absorbing device capable of effectively preventing plastic deformation of a loop portion by generating a stable frictional force when the loop portion is reduced in diameter. .
Another object of the present invention is to provide a metal fitting structure used therefor.

The present invention is an impact force absorbing device that absorbs an impact force acting on a wire, and forms a loop portion on the wire and a cross fitting that grips an intersecting portion where the wires intersect when forming the loop portion, A stopper fitting attached to a loop portion other than the intersection, and the intersection fitting is formed by connecting the first gripping portion and the second gripping portion, and connecting one wire of the intersection portion at the first gripping portion and the other gripping portion. The wire is individually gripped by the second gripping portion, and the wire gripping force of the first gripping portion and the second gripping portion is set to be smaller than the wire gripping portion of the stopper fitting, and the loop It is a part, Comprising: The ball or ring made into the shape of a bead is attached to the both sides or one side of a stopper metal fitting .

The cross metal fitting is a bolt that fastens the first metal fitting and the second metal fitting to form a first holding portion and a second holding portion between the first metal fitting and the second metal fitting. The second gripping portion may have a groove shape and a gripping force adjusting projection .
When the first metal fitting and the second metal fitting have a bolt fastening structure, the bolt can be fastened after adjusting the length of the wire and the formation position of the loop portion on site.
Conventionally, when the wire is thick, it is caulked at the factory, but the workability is excellent, and the loop part can be formed so as to avoid the obstacle part in the field.

  In this way, between the first metal fitting and the second metal fitting, the first holding part for holding one wire and the second holding part for holding the other wire are individually provided to reduce the diameter between the wires. They can no longer slide on each other.

Moreover, when the wire gripping force of the first gripping part and the second gripping part is set to be smaller than the wire gripping force of the stopper fitting, when the impact is applied to the wire and a tensile force is applied, the first gripping part and the second gripping part The one with the smaller wire gripping force relative to the part starts to slide first.
The first or second gripping portion that has started to slide is stopped by the stopper fitting.
Then, since the wire gripping force of the stopper fitting is larger than the first and second gripping forces, the next gripping portion of the first or second gripping portion is the one having the stronger gripping force.
That is, in the present invention, when one of the first and second gripping portions of the cross metal fitting slides, the other slides next, so that the loop diameter gradually decreases.
Thereby, a stable shock absorption amount can be obtained.

This invention is a loop part, Comprising: The ball or ring made into the shape of a bead is attached to the both sides or one wire of a stopper metal fitting, It is characterized by the above-mentioned.
Here, the reason is that on both sides or one side of the stopper metal fitting, a bead-shaped ball or ring is passed through the wire of the loop part to prevent the loop diameter from being reduced to a predetermined diameter or less. It is not always necessary to attach the bead-like balls or rings to both sides of the stopper fitting as long as it is provided on at least one side.
Further, the bead shape is used to prevent the ball or ring from moving with each other when the loop diameter is reduced, thereby preventing local bending of the wire and maintaining a state close to a circle.
Therefore, the size and number of balls or rings passed through in a bead shape are determined by setting the minimum diameter of the loop diameter.
In addition, the number of balls or rings is not limited as long as the number of balls or rings is one or more as long as local bending of the wire is prevented.

  In the impact force absorbing device according to the present invention, the intersecting portion in which the loop portion is formed on the wire is individually gripped by the first gripping portion and the second gripping portion of the cross fitting, and the gripping force is gripped by the wire of the stopper fitting. Since it was set to be smaller than the force, the wires can slide between each other in the past, whereas the invention according to the present application absorbs the impact force by the frictional force of the individual wire gripping portion in the cross metal fitting, so that the absorption stability is improved. high.

  Moreover, since it is a loop part and the ball | bowl or ring is passed between the stopper metal fitting and the cross metal fitting, the ball | bowl or ring can move mutually according to the change of R of the wire when a loop diameter becomes small. Therefore, local bending of the wire is difficult to occur, and when the ball or ring is sandwiched between the stopper metal fitting and the cross metal fitting, the loop diameter is not further reduced, so that the wire strength is effectively prevented from being lowered.

The impact force absorbing device according to the present invention can be widely applied in the technical field of absorbing impact force by reducing the diameter of the wire loop against resistance to friction.
As an example, FIG. 3 shows an example adapted to a wire 1 for supporting an avalanche, falling rock prevention shelf or prevention net 3 support 2 provided on a slope.

FIG. 1 shows a main part view of a portion in which a wire is formed in a loop shape and an impact force absorbing device according to the present invention is applied.
A ring-shaped loop 4 is formed in the middle of the wire 1, and a cross fitting 10 is attached to the crossing portion between the wires.
An example of the structure of the cross metal fitting 10 is shown in FIGS.
FIG. 4 shows a cross-sectional view of a state in which the first metal fitting 13 and the second metal fitting 14 are fastened, and FIG. 5 shows a plan view of the first metal fitting 13.
The cross metal fitting 10 has a structure in which the first metal fitting 13 and the second metal fitting 14 are fastened by the fasteners 15a and 15b. In the example shown in FIG. 4, the fastener includes bolts 16a and 16b and nuts 17a and 17b. Although it is a combination example, the fastener structure is not limited to this as long as it can grip the wire and adjust the gripping force.

Although only the first metal fitting 13 is shown in FIG. 5, the second metal fitting 14 has the same shape, and each wire at the intersection of the wires 1 is on the overlapping surface of the first metal fitting 13 and the second metal fitting 14. The first gripping groove 18a and the second gripping groove 18b for individually gripping each of the recesses B1 and B2 having a diameter slightly larger than the wire diameter in order to adjust the gripping force and the wire diameter for contacting the wire Projections A1 and A2 having small diameters are formed.
The gripping force of the wire is adjusted by the size and width of the protrusions A1 and A2.

  As shown in FIG. 4, the first holding part 11 and the second holding part for individually holding the wires intersecting the loop part 4 of the wire by the first metal part 13 and the second metal part 14 as shown in FIG. The part 12 is formed, and the first gripping part and the second gripping part are connected as one cross fitting.

As shown in FIG. 1, the crossing portion where the loop portion of the wire is formed is connected and held by the cross fitting as described above, and the stopper fitting 20 is attached to the inside of the loop portion.
An example of the structure of the stopper fitting 20 is shown in FIG.
The stopper fitting 20 is an example in which the wire 1 is sandwiched between two fittings 21 with bolts 22 and nuts 23 and fastened with bolts and nuts. The fastening force is set to be larger than the force.
Note that a wire gripping groove 24 is also formed between the two metal fittings 21 in the stopper metal fitting 20.

Balls or rings 31a, 31b,..., 32a, 32b,... Are passed between the cross fitting 10 and the stopper metal 20 of the loop portion 4 in a daisy chain.
This ball or ring is for maintaining a predetermined distance between the stopper and the cross metal fitting even when the loop is reduced in diameter, and each ball or ring is provided with a wire insertion hole. Are separated.
As long as the ball or ring achieves the above object, the material is not limited to metal, resin, etc., and the ball or ring may be a split ring or a C-shaped ring as long as it can cope with the R change of the loop. .
In the example shown in FIG. 1, balls or rings are provided on both sides of the stopper fitting 20, but only one side may be provided.

The operation of the impact force absorbing device according to the present invention will be described with reference to FIGS.
The shape of the loop attached to the avalanche, falling rock prevention fence or prevention net is as shown in FIG.
In contrast, when tension is applied to the wire 1, both ends of the wire 1 are fixed to the columns and the rock, so that a force in the pulling direction is applied to the wire gripping portion of the cross metal fitting 10.
The cross metal fitting 10 is holding the wire of the cross | intersection part of a loop part with the 1st holding part and the 2nd holding part individually.
Therefore, when tension is applied to the wire 1, a tensile force is applied to both the first gripping portion and the second gripping portion. However, in reality, both are less likely to slide against the friction force at the same time, and FIG. ), When one of the wire gripping portions starts to slide first, the static frictional force may be changed to a smaller dynamic frictional force, and the loop diameter becomes small so that the stopper fitting 20 approaches the cross fitting 10.
At this time, when the balls or rings 32a, 32b,... Are narrowed between the stopper fitting 20 and the cross fitting 10, as shown in FIG. The wire gripping force of the stopper fitting 20 is set to be higher than the gripping force of the remaining gripping portion that has not been slid by the cross fitting 10, so that the other ball or ring 31a, 32b,・ ・ ・ ・ The loop wire on the side becomes shorter and the loop diameter becomes smaller.
In this state, the diameter of the loop is not reduced by balls or rings 31a, 31b,... 32a, 32b,.

The principal part structure figure of the impact-force absorption apparatus which concerns on this invention is shown. The change of a loop part when tensile force acts on a wire is shown. The example of the avalanche and falling rock prevention net which applied the impact-force absorption apparatus which concerns on this invention is shown. The structural example of a cross metal fitting is shown. The structural example of the holding part of a cross metal fitting is shown. An example of the structure of the stopper bracket is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire 4 Loop part 10 Cross metal fitting 11 1st holding part 12 2nd holding part 13 1st metal fitting 14 2nd metal fitting 15a Fastening tool 18a, 18b Holding groove 20 Stopper metal fitting 31a, 32a A ball (ring)

Claims (1)

An impact force absorbing device that absorbs an impact force acting on a wire,
The wire includes a cross metal fitting that forms a loop portion and grips the cross portion where the wires cross each other when forming the loop portion, and a stopper metal fitting attached to the loop portion other than the cross portion. The gripping part and the second gripping part are connected and formed, and one wire at the intersecting part is gripped by the first gripping part, and the other wire is gripped by the second gripping part, respectively. And the wire gripping force of the second gripping part is set to be smaller than the wire gripping part of the stopper fitting ,
The impact force absorbing device according to claim 1, wherein a ball or ring in the form of a bead is attached to both sides or one wire of the stopper fitting .

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