JP6534149B2 - Shock absorption rope - Google Patents

Description

  The present invention relates to an impact absorbing rope, which is attached to a safety belt particularly used for preventing a fall in a high place operation, and supports the body and absorbs an impact when the operator falls from the high place. It relates to the rope to reduce it.

  In high-level work such as construction work and civil engineering work, safety belts for preventing falls are used, but in the event of a crash, the weight of the user impacts the user's abdomen through the safety belt Even if drowning was avoided, a strong impact on the abdomen could cause secondary injury.

  Therefore, safety belt structure guideline NIIS-TR-No. In the guidelines, the strength at break and the drop impact value are defined as the performance of the rope attached to the safety belt. That is, the strength at break is 15 kN or more, and the drop impact value is required to be 8 kN or less.

  Therefore, as a rope attached to the safety belt defined in such a guide, a rope that absorbs impact is used, and for example, a rope as described in JP-A-8-311787 (Patent Document 1) is known.

  The rope described in this patent document 1 uses high elongation fiber in the inner layer of each strand of the three-twisted rope, and uses low elongation nylon fiber in the outer layer, and high elongation when the user falls down. By stretching the fibers, it absorbs impact and nylon fiber bears the strength of the rope.

  However, in this case, the nylon fiber of the outer layer merely simply surrounds the inner layer, and the twisting makes the inner layer longer than the inner layer, so it is sufficient to stretch the inner layer. It can not absorb shocks.

Unexamined-Japanese-Patent No. 8-311787

  The present invention has been made in view of the above circumstances, and by making the strand of the rope a core-sheath structure, using a high elongation fiber as a core, and adopting a gold-hardened structure of a high strength fiber as a sheath body The purpose is to make the elongation of the sheath body sufficiently large to absorb a large impact.

  Thus, the present invention is a rope comprising a plurality of strands twisted or combined, wherein the strands have a core-sheath structure, and the core is a bundle of core yarns comprising high elongation fibers, and a sheath The body is characterized in that a sheath yarn made of high-strength fibers is folded around the periphery of the core body into a gold-hard punch.

  In the present invention, the core yarn is preferably made of an undrawn yarn or a low-drawn yarn of a synthetic fiber. The sheath yarn is preferably made of nylon or polyester fiber.

  In the present invention, it is preferable that a ratio of lengths of the core yarn and the sheath yarn is 1.5 or more of the sheath yarn with respect to the core yarn 1. Further, it is also preferable to mix a small amount of high-strength fiber into the core body.

  According to the present invention, the strands of the rope have a core-sheath structure, and a core yarn comprising high elongation fiber is used for the core body, and a sheathing yarn of high strength fiber is adopted as the sheath body for the sheath. I have a team.

  The metal string is a kind of braid, but the yarns constituting the metal string have a structure in which adjacent yarns are entangled with each other while the yarns constituting the string are helically rotated in one direction with respect to the length direction of the braid. .

  Therefore, it is possible to set the built-in length of the yarn longer as compared with a conventional braid in which the yarn is combined to the left and right with respect to the normal length direction, and when impact tension is applied, the yarn By unraveling the rotation and entanglement, the structurally large elongation is realized.

  Therefore, by using a high elongation fiber for the core body, a large elongation based on the above-mentioned gold-hardened structure of the sheath body is generated with respect to the elongation of the core body, compared to the one described in Patent Document 1 mentioned above. Can produce a large elongation and absorb a large impact.

Top view of the shock absorbing rope of the present invention Cross-sectional view of the shock absorbing rope of the present invention The top view which decomposed and showed a part of strand in the present invention SS curve of rope of Example 1 SS curve of rope of Example 2

  Hereinafter, the present invention will be described based on the drawings. FIGS. 1 and 2 show an example of the shock absorbing rope 1 of the present invention, in which the strands 2 are combined to form a cross rope having a braided structure. Although eight strands 2 are combined in the drawing, it is also possible to combine twelve strands, sixteen strands, or the like, or it is also possible to use a twisted rope in which three or four strands are combined.

  FIG. 3 shows a strand 2 in the impact absorbing rope 1 and has a core-sheath structure in which a sheath 4 surrounds the core 3.

  The core yarn 5 constituting the core body 3 is made of high elongation fiber. The high elongation fiber referred to in the present invention is a fiber having at least an elongation at break of 100% or more, and more preferably 150% or more.

  Furthermore, it is preferable to use an undrawn yarn or a low-drawn yarn as the core yarn 5. Usually, when producing a synthetic fiber, it is highly drawn to give strength, but an undrawn yarn means a fiber which is not subjected to the drawing. Low draw yarn is a fiber with a low degree of drawing.

  These undrawn yarns or low-drawn yarns have lower strength than ordinary drawn fibers, but when the tensile force is applied, the fibers are drawn and stretched so as to absorb the impact therebetween. It is to do.

  The sheath yarn 6 constituting the sheath body 4 is made of high strength fiber, and as the high strength fiber, synthetic fiber such as nylon or polyester to which normal stretching is applied can be used. The sheath body 4 is formed of a sheath-spun yarn 6 with a metal-rubbed structure, and the sheath body 4 is formed around the core body 3.

  As described above, while the sheath yarn 6 is spirally rotated in the longitudinal direction of the strand 2 as described above, adjacent sheath yarns 6 are intertwined with each other. Will be incorporated for a long time. In the present invention, the length of the sheath yarn 6 is preferably 1.5 or more with respect to the length 1 of the core yarn 5.

  According to the present invention, when a large tensile force is applied to the impact absorbing rope 1 in an impact, the core yarn 5 constituting the core 3 of the strand 2 is made of high elongation fiber, so the core 3 is greatly stretched. Be

  At the same time, the sheath body 4 of the strand 2 combines the sheath yarns 6 with a gold-stitched structure, so that the sheath yarns 6 of the gold-stiffened are extended by the unrotation of the sheath yarns 6, and the entanglement of the sheath yarns 6 is further entangled. Even if the sheath yarn 6 is extensible and the sheath yarn 6 is made of high strength fibers, a large elongation can be obtained.

  In addition, when the core 3 of the strand 2 becomes thin as it extends, the sheath 4 is spirally wound by gold-hardening, so that the angle of the sheath yarn 6 becomes strand 2 as the core 3 becomes thin. The sheath body 4 easily follows the core body 3 because the sheath body 4 also extends in parallel with the length direction of the sheath body 4.

  And if the shock absorption rope 1 is stretched to a certain extent, the extension of the sheath body 4 accompanying the gold-hardening of the sheath yarn 6 reaches the limit, and thereafter the limit of the strength of the high strength fiber constituting the sheath yarn 6 without extension. Thus, the shock absorbing rope 1 can withstand the pulling force without cutting.

  Further, in the present invention, by mixing a small amount of high strength fibers into the core body 3, the core body 3 is subjected to a tensile force under an impact and while the high elongation fibers are elongated, the high strength fibers are cut. And it can absorb shocks. About 5 to 20% of the core yarn 5 is suitable as the mixing amount of high strength fibers.

[Used yarn]
Partially drawn yarn of core yarn polyester multifilament 530 T × 14 (7420 T) Strength at break: 2.23 cN / T Elongation at break: 140%
Sheath yarn Polyester multifilament 1670 T × 3 (5010 T) Strength at break: 7.48 cN / T Elongation at break: 12%

[Strand]
Core body 7420 T / 10 (fiber consumption of core body: 55%) Aligned sheath body 5010 T × 12 P (fiber consumption of sheath body: 45%) Gim strike strand diameter: 5.75 mm Assembly: 9.3 mm / 4 strands Strand strength: 2.42 kN (core-sheath simultaneous maximum strength)

[rope]
Structure: Eight-stroke cross rope Lead: 80.5 mm
Rope diameter: 19.7 mm Rope weight: 200.5 g / m
Rope diameter after drop test: 17.0 mm

[Performance]
Breaking strength: 17.4 kN (Safety zone structure guideline: 15.0 kN or more)
Drop impact value: 3.76 kN (Safety band structure guideline: 8.00 kN or less)
Additional function: Expandable within 1,180 mm → 1,500 mm regardless of the basic performance of the rope

[SS curve]
The SS curve of the rope of the said Example 1 is shown in FIG. The origin O is in a state where no load is applied to the rope, and the elongation and the strength are both zero. The length of the sample at this time was 1180 mm, and in the SS curve, this time was taken as point O, and the displacement (mm) when pulled from this was taken on the horizontal axis. The vertical axis is the load (kN).

  And if a load is applied there, load will increase from O to A based on the structure of a rope, and a displacement will also become large in connection with it. When the load exceeds A, the structural deformation of the core 3 ends, and thereafter the core 3 receives a load and starts to expand, and the sheath 4 rotates and entangles the sheath yarn 6 based on the gold-hardening. It is extended by the solution of At this time, the sheath 4 does not bear the strength.

  The point at which the impact was absorbed when the impact load was received was point B, which was a load of about 3.7 kN, and the elongation was about 47%. As further load is applied, the S-S curve rises rapidly and breaks at point C. The strength at break was about 17.4 kN, and the elongation at break was about 110%.

  That is, when a person of ordinary weight receives impact of falling, the impact load is 3.7 kN, which is significantly lower than the safety band structure guideline 8.00 kN, and the person is subject to secondary damage. Absent. In addition, the strength at break is 17.4 kN, and even when a person who is heavier in weight uses it, it does not break.

  This embodiment is intended to make the diameter smaller and lighter than the previous embodiment, and a small amount of high-strength fibers is mixed in the core body 3.

[Used yarn]
Core yarn Polyester multifilament partially drawn yarn 530T x 14 (7420T) Strength at break: 2.23 cN / T Elongation at break: 140%
High strength fiber polyester multifilament 1100T x 3 (3300T) Strength at break: 7.48cN / T Elongation at break: 12%
Sheath yarn Polyester multifilament Black base yarn 940 T × 4 (3760 T) Strength at break: 6.05 cN / T Elongation at break: 23%

[Strand]
Core body 7420 T / 10 (fiber consumption of core body: 55.1%) Aligned 3300 T / one (fiber consumption of high strength fiber: 3.1%) mixed in sheath Body sheath body 3760 T × 12 P (sheath Fiber consumption of the body: 41.8%) Hardened steel Strand diameter: 5.20 mm Pair: 8.0 mm / 4 mountain Strand strength: 2.82 kN (core-sheath simultaneous maximum strength)

[rope]
Structure: Eight-stroke cross rope Lead: 69.0 mm
Rope diameter: 17.5 mm Rope weight: 142 g / m
Rope diameter after drop test: 15.5 mm

[Performance]
Breaking strength: 21.0 kN (Safety zone structure guideline: 15.0 kN or more)
Drop impact value: 5.07 kN (Safety band structure guideline: 8.00 kN or less)
Additional function: 1,120 m → → 1,500 m stretchable regardless of the basic performance of the rope

[SS curve]
The SS curve of the rope of the said Example 2 is shown in FIG. The origin O is in a state where no load is applied to the rope, and the elongation and the strength are both zero. The length of the sample at this time was 980 mm, which was taken as an O point.

  And when a load is applied there, the load increases from O to D based on the structure of the rope, and the elongation also increases accordingly. The high strength fiber mixed in the core 3 starts to break at D and repeatedly breaks to draw a serrated SS curve, while the load gradually increases with the increase of the elongation and the core yarn 5 Also extends. However, the sheath body 4 is extended by the rotation and entanglement of the sheath yarn 6 based on the gold-hardening, and the sheath body 4 does not bear the strength.

  The point at which the impact was absorbed when the impact load was received was point E, a load of about 5.0 kN, and an elongation of about 50%. As further load is applied, the S-S curve rises rapidly and breaks at point F. The strength at break was about 21.0 kN, and the elongation at break was about 128%.

  That is, when a person of ordinary weight receives impact of falling, the impact load is 3.7 kN, which is significantly lower than the safety band structure guideline 8.00 kN, and the person is subject to secondary damage. Absent. In addition, the strength at break is 17.4 kN, and even when a person who is heavier in weight uses it, it does not break.

1 Rope 2 Strand 3 Core 4 Sheath 5 Core Yarn 6 Sheath Yarn

Claims (5)

A rope (1) comprising a plurality of strands (2) twisted or combined, wherein the strands (2) have a core-sheath structure and the core (3) is a high elongation fiber (5) A shock-absorbing rope characterized in that the sheath body (4) is formed by bundling sheath yarns (6) made of high-strength fibers around the core body (3) in a metal-hardened manner. Impact-absorbing rope according to claim 1, characterized in that the core yarn (5) consists of undrawn yarn or low-drawn yarn of synthetic fibers. Shock-absorbing rope according to claim 1, characterized in that the sheath yarn (6) consists of nylon or polyester fibres. The yarn according to claim 1, characterized in that the ratio of lengths of the core yarn (5) and the sheath yarn (6) is 1.5 or more of the sheath yarn (6) with respect to the core yarn (5). Shock absorbing rope described The shock absorbing rope according to claim 1, wherein a small amount of high strength fiber is mixed in the core body (3).

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