JP5351797B2 - Textile rope for vehicle protection fence - Google Patents

Description

  The present invention relates to a fiber rope for a vehicle protective fence used for preventing a vehicle from departing from a roadway or partitioning a sidewalk on a road.

  Conventionally, as a guard fence for a vehicle used on a road, a guard rail in which a steel rail member is fixed to a support or a guard cable in which a plurality of cables are attached between the support is installed.

  In general, steel guardrails that are installed are subject to repeated deaths every year due to disasters such as the rails being damaged and piercing the vehicle at the time of a vehicle collision, and ensuring safety is an issue. In addition, steel guard cables mainly used in snowy areas have poor visibility, and there are drawbacks such as the cable growing in the summer due to temperature rise and requiring re-tensioning. Furthermore, in the case of a guard cable, when the cable is stretched, a load applied to the support column at the end portion increases, so that a trouble that the cable comes off at the end portion is likely to occur.

  As a rope used for such a guard fence, for example, in Patent Document 1, a steel element wire having a specific chemical component composition is drawn, twisted, and then subjected to austenite-forming heat treatment, so that the rope is very large. The point that energy absorption performance is provided is described.

JP 2007-191774 A

  Since the guard rail and the guard cable of the conventional vehicle protective fence are made of steel, when subjected to a load such as a strong impact or snow removal, plastic deformation and strength deterioration occur beyond the elastic range. Each time it is necessary to replace the member, the maintenance burden increases. Moreover, since the steel material has a low elongation, the impact received by the occupant during a vehicle collision is large.

  Although the point which raised energy absorption capability with the rope of steel materials is indicated in patent documents 1, since the energy absorption capability is raised by widening a plastic deformation zone, the problem that the exchange frequency of a member will become rather high There is.

  In addition, the fiber rope is hard to be plastically deformed except for the initial elongation in the low load region, and has a high impact absorption capability. However, the conventional commercially available fiber rope has a problem that the strength is insufficient for the unit weight. .

  Accordingly, an object of the present invention is to provide a fiber rope for a protective fence for a vehicle that has the same strength and weather resistance as that of a conventional steel product and has improved workability and impact absorption.

  A fiber rope for a vehicle protective fence according to the present invention is a double-structured fiber rope for a vehicle protective fence provided with a core portion and a covering portion covering the core portion, and the covering portion has weather resistance. It has a braided structure of twelve or more struts in which 12 or more strands are combined without gaps, and the core portion is formed by combining 12 or more strands and the lead is set to 6 times or more the outer diameter of the core portion. It consists of a braid structure. Furthermore, the strand of the said coating | coated part consists of a carbodiimide group containing synthetic fiber or a carbon black containing synthetic fiber.

  By providing the above-described configuration, the present invention can configure a fiber rope for a vehicular protective fence that has the same strength and weather resistance as those of conventional steel products, and has improved workability and impact absorption.

  That is, since the core of the fiber rope is composed of a braid structure in which 12 or more strands are combined and the lead is set to be 6 times or more the outer diameter of the core, the strength that can withstand the impact at the time of vehicle collision It is possible to minimize the damage to the vehicle and the occupant by absorbing and absorbing the impact. In particular, since the fiber rope has a higher elongation than a steel cable, it has a large impact absorbing function, and even if it breaks, there is almost no damage to the vehicle or passengers.

  In addition, since the covering portion of the fiber rope has a weather resistance and is composed of a twelve-strand braid structure in which 12 or more strands are combined without gaps, the strands are combined in a close contact state without gaps, and sunlight is combined. It can prevent that the fiber which shields and comprises a core part deteriorates with sunlight. Therefore, it is possible to suppress a decrease in the strength of the fiber rope due to deterioration over time, and it is possible to reduce a maintenance management burden such as maintenance.

  In addition, if the fiber rope is made of a flexible lightweight material such as synthetic fiber, it is possible to easily construct a guard fence for vehicles, and the mounting structure compared to the case of attaching a heavy object such as steel to the guard cable. Can be simplified. Moreover, since the resilience against deformation is great, it has sufficient durability against snow damage and hardly deteriorates against salt damage that occurs when it is installed on the coast.

It is a block diagram regarding the fiber rope for vehicle guard fences concerning this invention. It is explanatory drawing regarding calculation of allowable displacement amount. It is a table | surface which shows the measurement result of the breaking strength of a fiber rope. It is a graph which shows transition of the tension | tensile_strength and elongation in the tension test using a fiber rope. It is a table | surface which shows the result of the performance confirmation test of a fiber rope. It is a table | surface which shows the result of the weather resistance test of a fiber rope.

  Hereinafter, embodiments according to the present invention will be described in detail. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  FIG. 1 is a configuration diagram relating to a fiber rope A for a guard fence for a vehicle according to the present invention. The fiber rope A has a double structure of a core part 1 and a covering part 2 covering the periphery of the core part 1, and the core part 1 has a twelve-strand braid structure by combining 12 strands. Twenty-four strands are combined in one set to form a twelve-strand braid structure with no gaps. The core portion 1 and the covering portion 2 may each be configured by a double braided braid structure in which 12 or more strands are combined.

  The core part 1 and the covering part 2 have an independent braid structure, and can be separated. Therefore, when the vehicle collides at a shallow angle with respect to the fiber rope, the covering portion first breaks and slips on the core, preventing the vehicle from directly biting into the core and causing damage. It is like that.

  The lead 1 is set to the core portion 1 with a length of 6 times or more the outer diameter D of the core portion 1. The lead is a twist of one strand (about), and the larger the value of the lead, the more the strands are combined in a loose state where the twist is weak. On the other hand, the covering portion 2 has a braid structure of twelve or more strikes and the strands are combined in a clogged state with no gaps. Therefore, even when the strand 10 of the core portion 1 is weakly twisted and swells in the radial direction, the strand 20 of the covering portion 2 acts to suppress the swelling of the strand 10 of the core portion 1 from the periphery, and the handling of the fiber rope And the core portion 1 can be protected by the covering portion 2. And if an impact force is added to the core part 1 when a vehicle collides, the core part 1 will expand | extend and an impact force will be absorbed.

  Since the core part 1 and the covering part 2 are configured by the same braid structure, the covering part 2 can be formed simultaneously with the core part 1 by a known braiding device when manufacturing, and the manufacturing efficiency can be improved. Is possible. If the strands are combined without twisting to form a braid structure, the entire fibers constituting the strands contribute to the tensile strength, and the tensile strength can be increased.

  As the strand constituting the fiber rope, a fiber bundle made of synthetic fibers may be used. Synthetic fibers include, for example, polyamide fibers such as nylon, polyester fibers, polyacrylonitrile fibers, polyvinyl alcohol fibers such as vinylon, polypropylene fibers, polyvinyl chloride fibers, polyethylene fibers, and polyvinylidene chloride fibers. Polyurethane fibers are mentioned, but polyester fibers are preferred from the viewpoints of strength to withstand impact, elongation to absorb impact, and corrosion resistance, heat resistance and moisture resistance when installed outdoors.

  As the strand constituting the covering portion 2, a strand made of a synthetic fiber having weather resistance is used. For example, if synthetic fibers containing carbon black or synthetic fibers containing carbodiimide groups are used, durability against ultraviolet rays contained in direct sunlight can be provided. Since the coating | coated part 2 is comprised in the state with which the strand was clogged without the clearance gap, it can shield a direct sunlight reliably and can prevent the aged deterioration of the strand which comprises the core part 1. FIG.

  The strand constituting the core portion 1 preferably has a fineness of 800 dtex to 2100 dtex. If the fineness is smaller than 800 dtex, sufficient strength cannot be obtained, and if the fineness is larger than 2100 dtex, it becomes difficult to use as a protective fence for a vehicle when combined with 12 or more strands. Moreover, the strand which comprises the coating | coated part 2 has a fineness of 800 decitex-2100 decitex.

  When examining the strength of fiber ropes required for vehicle fences, the Ministry of Land, Infrastructure, Transport and Tourism has established installation standards for road fences (revised by National Highway No. 93, revised in March 2004). For general roads, the road side type B (vehicle collision speed 60 km / h) determined by the installation standards is set to an impact level of 60 kJ or higher.

Therefore, the tensile strength of the fiber rope that can withstand such a degree of impact was calculated based on the following setting conditions.
(1) It is assumed that the impact is handled by four fiber ropes stretched between the columns.
(2) The distance between the intermediate struts of the protective fence for vehicles using fiber ropes is assumed to be three types of 6m, 7m, and 8m. In order not to deviate from the end, an allowable displacement amount in the direction perpendicular to the road is set from the original position of the fiber rope. As shown in FIG. 2, the allowable displacement amount is determined such that the approach angle θ of the design vehicle C (the length from the front wheel to the front surface is 1.5 m and the length from the front wheel to the side surface is 0.3 m) is the longitudinal direction of the fiber rope A. On the other hand, when the angle is set to 15 ° and the distance between the fiber rope A and the road end R is set to 0.3 m, the allowable displacement d is calculated as follows.
d = 1.5 m × sin 15 ° + 0.3 m × cos 15 ° + 0.3 m = 0.95 m
(3) The tension is set to 30 kN on the fiber rope at the time of installation so that the tension and elongation of the fiber rope are proportional (shows linearity).

  As a result of analysis to satisfy the above setting conditions, it was found that the tensile breaking strength of the fiber rope should be set to 230 kN or more in order to correspond to the road B type.

  Next, the tensile strength test was performed by changing the number of strands and the lead value of the fiber rope configured with the braid structure. A fiber rope having a nominal diameter of 35 mm and a polyester fiber (manufactured by Toray Industries, Inc.) having a fineness of 1670 dtex was prepared as a strand. In the tensile strength test, a fiber rope was set in a constant speed tension type tensile tensile tester in accordance with JIS L2707-1992 and the breaking strength was measured. The measurement results are shown in FIG. The lead value was set as a multiple of the outer diameter of the core.

  From this measurement result, the number of strands is 12 or more, the lead value is 6 times or more the outer diameter of the fiber rope, and the tensile strength at break is 230 kN or more. This is because the strands become closer to a straight line as the number of strands and the lead value increase, so the adhesion force applied between the strands when applying a tensile load is reduced, and the shear stress in the radial direction of the strands is reduced, This is considered to be difficult to break.

  When the fiber rope of the present invention has a double structure, the tensile force is mainly applied to the core, so the number of strands in the core is 12 or more and the lead value is outside the core. What is necessary is just to set to 6 times or more of a diameter.

  In the measurement results shown in FIG. 3, when the number of strands is 3 and 8 and the lead value is 8 times or more, the measurement becomes difficult. This is because it occurs and cannot be measured accurately.

  FIG. 4 is a graph showing changes in tension (kN) and elongation (%) in a tensile test using a fiber rope set with 12 strands and a lead value of 6 times. As shown in FIG. 4, as the tension increases, the fiber rope stretches by about 20% until it breaks. Therefore, it can be seen that when an impact force is applied to the fiber rope, the fiber rope extends to absorb the impact.

Next, a fiber rope was actually stretched between the columns to perform a performance confirmation test. The fiber rope had a nominal diameter of 35 mm and a double structure of a core part and a covering part, and a polyester fiber (manufactured by Toray Industries, Inc.) was used as a strand. The core has a braided structure using 12 strands of 1670 dtex and the lead value is set to 6 times the outer diameter of the core, and the covering portion is twelve clogged with 12 strands of 1670 dtex. A striking braid structure. Then, a guard fence to which four steel guard cables were attached was used, and instead of the guard cables, four fiber ropes were attached at intervals of 13 cm up and down. The test method was performed in accordance with “Test Method for Confirming Performance of Guard Fence for Vehicle” (November 5, 1998, Ministry of Construction, Road Bureau, Road Environment Division Director). The intermediate struts of the protective fence were built in the soil, and the distance between the intermediate struts was set to 6m, 7m, and 8m, and the vehicle was made to collide with the fiber rope. The collision speed and the collision angle of the vehicle were calculated by analyzing the image of the high-speed photographing camera. The measurement results are shown in FIG. The reference for the separation speed is 60% or more of the collision speed, and the reference for the separation angle is 60% or less of the collision angle. The acceleration (m / s ² / 10ms) is the maximum value of 10ms moving average of resultant acceleration measured in two horizontal directions accelerometers in the vehicle center of gravity.

  In the measurement result shown in FIG. 5, when the intermediate strut interval is 6 m, the collision angle is smaller than the reference and the impact level does not satisfy the reference. However, when the intermediate strut interval is wide, 7 m and 8 m, Results satisfying standard values and criteria were obtained.

  When the vehicle collided, the covering portion of the fiber rope peeled and the core portion was exposed, but the core portion itself was not broken and the vehicle did not jump out of the road. Therefore, it can be said that the covering part also functions to protect the core part in the event of a collision. In addition, the core portion was extended at the time of the collision, so that the impact was absorbed and the vehicle and the occupant were not seriously damaged.

  Based on the above-described test results, the core is composed of a braid structure in which 12 or more strands are combined to set the lead to be 6 times or more the outer diameter of the core, and the covering portion covering the core is 12 By using a double-structured fiber rope composed of twelve or more braided structures that combine more than one strand without gaps, it can be used as a vehicle protective fence that fully meets the installation standards. .

  Next, the weather resistance test at the time of using the strand which consists of a synthetic fiber provided with a weather resistance in a coating | coated part was done. The fiber rope has a nominal diameter of 30 mm and a double structure of a core part and a covering part. The core part has 16 strands (carbodiimide group-containing fibers, fineness 1100 dtex manufactured by Unitika Ltd.) and the lead value is the outer diameter of the core part. The braid structure was 8 times, and the covering part was composed of a 12-strand braid structure clogged with 12 strands (carbodiimide group-containing fiber, fineness 1100 dtex) manufactured by Unitika Ltd. The test method was performed using a sunshine carbon arc lamp type light resistance and weather resistance tester based on JIS B7753. And the tensile breaking strength of the fiber rope was measured using the constant-speed tension type | mold tension test machine based on JISL2707-1992 before irradiation and for every predetermined irradiation time. The measurement results are shown in FIG.

  The tensile strength retention rate (%) is the ratio of the measured strength after irradiation to the tensile breaking strength measured before irradiation (irradiation time is 0). From the measurement results, it can be seen that, after 25 years (3750 hours), the decrease in tensile strength is suppressed to about 13%, and it has weather resistance comparable to that of a steel protective fence.

  Moreover, as a fiber rope, the nominal diameter is 30 mm and it has a double structure of a core part and a covering part, the core part is 16 strands (carbon black containing fiber manufactured by Toray Industries, Inc., fineness 1100 dtex), and the lead value is outside the core part. Using a braid structure having a diameter of 8 times the diameter, and a covering portion having a twelve-strand braid structure clogged with 12 strands (carbon black-containing fiber manufactured by Toray Industries, Inc., fineness 1100 dtex) When the same test as the weather resistance test described above was performed, it was found that the steel guard fence and the weather resistance comparable to those of steel were provided.

A Fiber rope for vehicle protection fence 1 Core 2 Covering part
10 strand
20 strand

Claims (3)

  A fiber rope for a vehicular protective fence having a core portion and a covering portion that covers the core portion, wherein the covering portion has a weather resistance and is a combination of 12 or more strands without gaps. A vehicular protective fence comprising a braid structure of two or more strokes, wherein the core portion has a braid structure in which 12 or more strands are combined and a lead is set to 6 times or more the outer diameter of the core portion. Fiber rope.   The strand of the said coating | coated part consists of a carbodiimide group containing synthetic fiber or a carbon black containing synthetic fiber, The fiber rope of Claim 1 characterized by the above-mentioned.   A vehicular protective fence in which the fiber rope according to claim 1 is stretched between columns.

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