JP4896167B2 - Energy absorbing belt - Google Patents

Description

  The present invention relates to an energy absorbing belt.

  Conventionally, as this kind of impact energy absorbing belt, as disclosed in Japanese Utility Model Laid-Open No. 49-11428 (Patent Document 1) or Japanese Patent Application Laid-Open No. 50-4725 (Patent Document 2), etc. An energy-absorbing belt composed of a single-layered fabric composed of a plurality of types of warp yarns having different elongations at the same time, wherein a part of the plurality of types of warp yarns is floated and woven from other warp yarns. Are known.

  However, in such a known example, since it is composed of one layer of woven fabric and at least two kinds of warp yarns are cut in the extension process of the energy absorbing belt, the energy absorbing belt as a whole When seen, the strength was insufficient and the reliability related to safety was poor.

  On the other hand, as an energy absorbing belt in which woven fabrics are arranged in two layers, for example, as disclosed in Japanese Patent Application Laid-Open No. 2003-275333 (Patent Document 3), upper and lower woven fabrics are joined to each other with twine yarns. The present invention discloses an energy absorbing belt that uses a plurality of types of core yarns having different cutting elongations, and the ground yarn is not cut with the extension of the energy absorbing belt, but only the core yarn is sequentially cut. Has been.

  However, in such an energy absorbing belt, since it uses multiple types of core yarns and entanglement yarns, it has the disadvantage that the production cost increases because the weaving process is complicated, Since the cutting of the core yarn occurs partly and intensively, the impact that the operator receives in the event of an accident is generated in stages, and thus there is a disadvantage of feeling uncomfortable.

  Therefore, conventionally, there has been a demand for an energy absorbing belt that is sufficiently strong, has a high energy absorbing effect, greatly reduces the impact on falling objects, has a low cost, and is highly reliable for safety.

Japanese Utility Model Publication No. 49-11428 Japanese Patent Laid-Open No. 50-4725 JP 2003-275333 A

  Accordingly, an object of the present invention is to solve the problems in the conventional energy absorption belt described above, and to show an ideal breaking / extension characteristic while having a simple configuration. An energy absorbing belt that has sufficient durability and strength to protect it, and still provides an energy absorbing belt that is highly productive and can reduce production costs. It is an object of the present invention to provide an energy absorbing belt capable of efficiently receiving objects over a wide range and expanding the range of workers or users to be protected.

  In order to achieve the above-described object, the present invention employs a technical configuration as described below. That is, the basic configuration of the energy absorbing unit according to the present invention is an energy absorbing belt, which is arranged in two layers on the front and back sides, and the first fabric and the first fabric that are connected to each other by tangled yarn. Each of the first and second fabrics has a plain weave structure, and each of the fabrics has at least three warp yarns having different elongation characteristics and breaking strength. And at least one type of weft, at least one type of warp is a high elongation yarn with a breaking elongation of 100% or more, and the other warp yarn is a combination of chopped yarns with a breaking elongation of 35% or less. It is configured to continue to absorb energy when the belt impact load is applied, even after energy absorption due to breakage of the cut yarn, and the high elongation yarn continues to stretch. It is the energy absorption belt characterized.

As described above, in the present invention, an energy absorbing belt composed of a two-layered plain woven fabric, and in each plain woven fabric without using a core yarn, by selecting the characteristics of three types of ground yarn, The balance of the applied state of the load in the belt can be improved, and each of the first warp yarns 4-1 which are particularly chopped yarns in the ground yarn can be absorbed in sequence while being uniformly dispersed in the belt. In addition, it can be configured so that the cutting of the ground yarn accompanying it occurs, thereby controlling the extension of the second warp yarn 4-2, which is a high elongation yarn having a breaking elongation of 100% or more, and the energy absorption area of the belt. It can be arbitrarily set, and the third warp can maintain sufficient strength to ensure safety.

Since the present invention basically employs the technical configuration as described above, the following operational effects can be exhibited.
That is, it is an energy absorbing belt that has an ideal breaking extension characteristic as shown in FIG. 2 and has a sufficient durability during use even though it has a simple configuration, and has high productivity and low production cost. It has the effect that an energy absorbing belt that can be suppressed can be easily obtained.

  Furthermore, in the present invention, an energy absorbing belt having sufficient durability and strength to protect workers or users in the event of an accident, which can greatly reduce the load limit of falling objects. It can be efficiently received over a wide range from falling objects with low loads to falling objects with high loads, and the scope of workers or users who are subject to safety protection can be expanded. By providing an energy absorbing belt, it has become possible to easily and inexpensively obtain an energy absorbing belt in which the drawbacks of the conventional energy absorbing belt are improved.

FIG. 1 is a cross-sectional view showing a configuration of one specific example of an energy absorbing belt in the present invention. FIG. 2 is a diagram showing a tensile strength / elongation curve of one specific example of the energy absorbing belt in the present invention. FIG. 3 is a diagram showing an example of a tensile strength / elongation curve of each warp (ground yarn) constituting one specific example of the energy absorbing belt in the present invention. FIG. 4 is a diagram showing an example of a drop impact test apparatus for performing a drop impact test of the energy absorbing belt in the present invention. FIG. 5 is a diagram showing a tensile strength / elongation curve in the present invention and a comparative example of the present invention. FIG. 6 is a diagram showing an impact load waveform of the energy absorbing belt when the object to be dropped is 85 kg using the energy absorbing belt in the present invention. FIG. 7 is a diagram showing an impact load waveform of the energy absorbing belt when the object to be dropped is 100 kg using the energy absorbing belt in the present invention. FIG. 8 is a diagram showing an impact load waveform of the energy absorbing belt when the object to be dropped is 120 kg using the energy absorbing belt in the present invention. FIG. 9 is a diagram showing an impact load waveform of the energy absorbing belt when the object to be dropped is 140 kg using the energy absorbing belt in the present invention. FIG. 10 is a diagram showing an impact load waveform when an object to be dropped of one specific example of the energy absorbing belt in the present invention is 85 kg. FIG. 11 is a diagram showing an impact load waveform when the fall target of one specific example of the energy absorbing belt in the present invention is 100 kg. FIG. 12 is a diagram showing a tensile strength / elongation curve when the object to be dropped of the energy absorbing belt in Patent Document 3 is 85 kg. FIG. 13 is a waveform diagram showing an impact load waveform when the object to be dropped of the energy absorbing belt in Patent Document 3 is 100 kg. 14 (A) to 14 (E) are graphs showing the test results of the energy absorbing belt in the present invention. FIG. 15 is a grab showing the influence of the first warp on the second warp in the present invention. FIG. 16A is a waveform diagram showing an impact load waveform of a nylon rope, and FIG. 16B is a waveform diagram showing an impact load waveform of the energy absorbing belt in the present invention.

Hereinafter, an example of a configuration according to a specific aspect of the present invention will be described in detail with reference to the drawings.
That is, FIG. 1 is a diagram showing an example of the configuration of a specific example of the energy absorbing belt 1 according to the present invention. In FIG. The first fabric 2 and the second fabric 3 are connected to each other by the leash yarn 7, and each of the first and second fabrics 2 and 3 includes at least three types of warp yarns 4. And at least one kind of weft yarn 5 so as to have a plain weave structure. Among the warp yarns 4, the first warp yarn 4-1 (hereinafter simply referred to as the first warp yarn) is a cut yarn. A second warp yarn 4-2 (hereinafter simply referred to as a second warp yarn), which is composed of a yarn that is cut at a predetermined tensile strength and is a high elongation yarn having a breaking elongation of 100% or more, is hereinafter referred to as a second warp yarn. It is composed of a yarn having a high stretch characteristic that stretches without being cut, and a third warp yarn 4- 3 shows an energy absorbing belt 1 having a high strength characteristic and being woven into the fabric so that the yarn foot 6 is longer than other warp yarns.

  And the core yarn as shown in the above-mentioned patent document 3 is not used for any of the first and second fabrics 2 and 3 in the present invention, or the first and second fabrics are used. The core yarn is not used in the intermediate portion of the fabrics 2 and 3, that is, the boundary portion thereof.

  In the present invention, by adopting such a configuration, the weaving process of the energy absorbing belt 1 can be simplified and improved in efficiency, and further, the balance of the load application state in the belt can be improved, As a result, it is possible to disperse the places where the impact load is generated when the object (operator, etc.) is dropped when an accident occurs, and to reduce the impact received by the object. Specifically, when the second warp used in the present invention is to be stretched in response to an impact at the time of an accident, the first warp is sequentially cut at equal places. Since the second warp acts so as to prevent the second warp from being excessively stretched, the second warp is stretched while absorbing energy uniformly and slowly. In other words, in the present invention, the above-described effects are achieved by the exquisite synergy between the extension operation of the second warp and the extension suppression operation of the first warp.

  The first to third warps used in the present invention are not particularly limited in the fineness, the number of filaments, or the number of twists, but all are nylon, polyester, polypropylene synthetic fiber or aramid fiber, Preferably, the first to third warp yarns may be made of the same synthetic fiber, or may be composed of at least one synthetic fiber selected from carbon fibers or the like. May be composed of different synthetic fibers.

  As specific examples of the first to third warp yarns in the present invention, any of them may be made of nylon or polyester synthetic fiber. In some cases, the nylon and polyester synthetic fiber may be used. You may mix and use a fiber.

  On the other hand, the weft used in the present invention is not particularly limited in the fineness, the number of filaments, etc., but any of them is at least one selected from nylon, polyester, polypropylene synthetic fiber, aramid fiber, carbon fiber, etc. It is desirable to be composed of two synthetic fibers.

The fineness and the number of filaments of each warp and weft in the present invention can be arbitrarily determined in consideration of the necessary characteristics of the fabrics 2 and 3.
If it demonstrates further with reference to FIG. 3, it is desirable that the said 1st warp 4-1 used in this invention has a fracture | rupture characteristic that it cut | disconnects more than predetermined tensile strength. .

  In addition, the second warp 4-2 used in the present invention has a high degree of stretch characteristics, and the tensile strength or cutting that the first warp 4-1 cuts is progressing. It is preferable that the tensile strength is such that only stretching is continued without cutting.

On the other hand, it is desirable that the third warp 4-3 is a high strength yarn that has the highest tensile strength among all the warps used in the present invention and is not cut to the end.
In the above-mentioned Patent Documents 1 and 2, a plurality of types of yarns having different cutting elongations are used for the ground warp constituting the belt, and the local warp is sequentially and all along with the extension of the energy absorbing belt. It is configured to absorb impact energy by cutting, and Patent Document 3 uses two types of core yarns having different cutting elongations that are not incorporated in the basic structure of the fabric. In the present invention, the core yarn is not used at all, whereas the core yarn is configured so as to finally cut all of the core yarn and absorb the impact energy. The above-described three types of warp are used as the ground warp of the energy absorbing belt.

  That is, in the present invention, as a result of adopting the above-described technical configuration, when a predetermined impact load is applied to the first warp 4-1, the first warp 4-1 Breaks occur sequentially at partially and randomly dispersed sites, and in the meantime, the second warp yarn 4-2 is gradually stretched without being cut, and all the first warp yarns 4-1 are broken. After that, it will behave so as to absorb the impact load while continuing to stretch.

  Furthermore, in the present invention, as described above, since the extension operation of the second warp can be controlled by the extension suppression operation by the first warp, the above-described effects are achieved. .

  After that, while the second warp yarn 4-2 continues to be stretched, the third warp yarn 4-3 gradually receives tension, and is formed to project on the surface of the fabric in the pre-given loop shape. Until the thread foot portion 6 disappears, it is stretched in the same direction as the second warp thread 4-2, further absorbs impact energy, and the second warp thread 4-2 and the third warp thread 4-3 are The impact energy absorbing action of the energy absorbing belt is completed at the time when both are in a straight state and in a parallel state or just before the parallel state.

  Then, when the energy absorbing belt 1 completes the impact energy absorbing function, the second and third warps 4-2 and 4-3 are not cut together, and both warps cooperate to load. Will be held.

  That is, it is desirable that the third warp 4-3 used in the present invention is the yarn having the highest strength among a plurality of types of warp used in the present invention. As shown in FIG. 1, the third warp thread 4-3 is woven in a state where the thread foot is set longer than the thread foot of the other warp thread.

By the way, the length of the thread foot 6 of the third warp thread 4-3 in the present invention is not particularly limited, but may be determined in relation to the elongation of the second warp thread. preferable.
Such a woven structure can be realized, for example, by setting the tension of the third warp 4-3 lower than the tension of other warps.

  That is, in the present invention, the third warp thread 4-3 enables the entire woven structure of the energy absorbing belt 1 to be stretched while the second warp thread 4-2 continues to be stretched. Thereby, the second warp yarn 4-2 is supported to be fully stretched.

  The difference in the weaving length of the third warp 4-3 with respect to the second warp 4-2 is preferably, for example, 100 mm to 500 mm per 1 m of the plain fabric.

〔Example〕
Below, the Example of the energy absorption belt 1 which concerns on this invention is described.
The energy absorbing belt according to the present invention was manufactured on a trial basis with the following specifications, and the characteristics thereof were measured.

  In the present embodiment, the number of the first warp used is appropriately changed from 0 to 24 / 20.8 mm, and the first warp is characteristic when the first warp is used and not used. At the same time as making the difference clear, the experiment was performed by changing the drop load appropriately between 85 kg and 140 kg.

Specification of energy absorbing belt according to the present invention:
The width of the belt: 20.8 mm,
The first and second fabrics constituting the belt are composed of a plain weave structure (1/1 flat double structure, warp density: 248 / 20.8 mm, weft density: 17/30 mm), and yarn The specifications were as follows for both fabrics.
(1) First warp Nylon-6, 1400 T / 1 (60 t / m) Tensile strength 8.39 cN / dtex (breaking elongation: 35%), density 0 to 24 / 20.8 mm,
(2) Second warp polyester 2110T / 1 (300 t / m) Breaking elongation: 140%, density 116 / 20.8 mm,
(3) Third warp Nylon-6, 1400 T / 2 (120 t / m) Tensile strength 8.39 cN / dtex (breaking elongation: 35%), density 104 pieces / 20.8 mm,
(4) Entangled yarn Polyester 2110T / 1 (300 t / m) Elongation at break: 140%, density 4 / 20.8 mm,
(5) Weft Yarn Nylon-6, 1400 T / 1 (60 t / m) Tensile strength 8.39 cN / dtex (breaking elongation: 35%), density 17 pieces / 30 mm,
In the above specific example, the third warp yarn reduces the tension applied to the warp yarn during weaving compared to the other warp yarns, that is, the first and second warp yarns. Weaving was adjusted to be longer than other warp yarn legs.

  After the belt is completed, the length of 1 m is cut out in the warp direction of the belt, each warp is disassembled, and the weaving length for the 1 m is measured. As a result, the third warp is the first and second It was found that, on average, it was woven 490 mm longer than the warp yarn.

  Here, in order to grasp the dynamic characteristics of the energy absorbing belt 1 according to the present invention, a test was conducted using a drop impact test apparatus 40 shown in FIG. Specifically, a drop of 1.7 m with a weight of the object to be dropped of 85 kg with respect to each sample in which the number of the first warp used was changed to 0, 8, 16, 20, and 24 While performing the test, for the sample in which the number of the first warps is fixed to 24, a drop test of 1.7 m is performed while changing the weight of the object to be dropped from 85 kg to 140 kg, and each drop is performed. The impact load and elongation at the time were measured, and as a result, elongation data and impact load waveforms as shown in Table 2 and FIGS. 6 to 9 and FIGS. 14A to 14E were obtained.

  The drop impact test apparatus 40 shown in FIG. 4 is provided with a load cell 42 connected to a control measuring means 48 including an appropriate control device and an appropriate measurement circuit in an appropriate shaft 41, and is suspended by the load cell 42. The first chuck portion 43 is attached, and the second chuck portion 44 to which the weight 46 is connected is configured to freely fall in the shaft 41 together with the weight 46, and the first and second chuck portions 43 are configured. , 44 is attached with an energy absorbing belt 45 to be measured.

In the present invention, the length between the first and second chuck portions 43 and 44 is set to 1.7 m, but the present invention is not limited to this.
The weight 46 is held at a predetermined position by an appropriate stopper 47 before the test is executed, and the weight 46 is released by releasing the stopper 47 by an instruction signal from the control measurement means 48 when the test is executed. It is configured to drop.

  As can be understood from FIGS. 6 to 9, in the sample in which the number of the first warps used is fixed at 24 / 20.8 mm, the drop load is changed between 85 kg and 140 kg. Even in this case, in the energy absorbing belt 1 according to the present invention, the impact load value rises instantaneously immediately after the impact is applied. However, when the impact load is in the vicinity of 4.50 kN, the first warp is directly applied. Since the impact energy is gradually absorbed by starting cutting, the impact load value does not increase and maintains a substantially parallel value. 2 and the third warp cause an effect on the increase in load on the belt elongation, and the waveform swells upward, but the second warp and the third warp cause the energy absorbing belt 1 to Disconnected Ku and it is shown to return to the gentle stationary state.

  For this type of energy absorbing belt, considering that the national safety standard, which is a safety band standard, is set to “impact load of 8.0 kg or less when dropping 85 kg-1.7 m”, the present invention It is extremely ideal as an energy absorbing belt that the obtained impact load is 4.5 kN or less.

On the other hand, the present inventor conducted a test similar to the above using the energy absorbing belt produced based on the example of Patent Document 3 described above, and the results are shown in FIGS.
FIG. 12 shows an impact load waveform when a load of 85 kg is attached and dropped by 1.7 m using the energy absorbing belt manufactured based on the example of Patent Document 3 described above. FIG. 13 shows an impact load waveform when a load of 100 kg is attached to the same sample as above and dropped by 1.7 m.

10 and 11 compress the time axis in order to match the same impact load waveform as that shown in FIGS. 6 and 7 in the present invention to the time axis of the impact load waveform in FIGS. This is a modified display for the purpose of facilitating the comparison between the two.
That is, FIGS. 10 and 12 and FIGS. 11 and 13 correspond to the test methods, respectively.

  When both are compared, the energy absorption belt obtained by Patent Document 3 also shows an impact load curve approximated to the impact load curve exhibited by the energy absorption belt according to the present invention. Since the belt is premised on that all core yarns are cut, during the impact energy absorption period immediately after the impact is applied, the shock load waveform has a vibration state with a fine amplitude as in the present invention. As shown, the waveform of Patent Document 3 has a considerably long period of absorbing impact energy, and the amplitude of each of the waveforms is large. Therefore, even while absorbing the impact energy, fine vibrations are constantly generated. Since it is added to an object (such as a falling worker), there is a problem that the object is constantly subjected to unpleasant impacts.

  However, in the energy absorption belt 1 according to the present invention, the amplitude of the impact waveform is smaller than the amplitude of the same waveform in Patent Document 3, and the period during which the impact energy is absorbed is considerably short. The problem of unpleasant impacts on objects is solved.

  On the other hand, in the energy absorbing belt obtained by Patent Document 3, when the weight exceeds 100 kg, the waveform of the end portion of the impact load curve increases sharply, and still shows a convex waveform having a large amplitude. .

  The waveform of the end portion of the impact load curve of the energy absorbing belt obtained by the Patent Document 3 becomes steeper and shows a more intense amplitude as the load further increases.

  In such characteristics, the energy absorbing belt cannot absorb the shock completely during the impact energy absorption process, and a large load is instantaneously applied to the object at the final stage of the shock energy absorption process. It is clear that a very dangerous state will occur in the target object (such as a falling worker), and the target object (such as a falling worker) is more dangerous and uncomfortable. There is a problem of being shocked.

  In the present invention, the difference is that, in addition to the plain weave structure being a plain weave structure, the second warp yarn continues to be stretched without being cut even while the first warp yarn is being cut. The impact load applied to the first warp is moderately dispersed, and the belt is not stretched partly and the belt is gradually stretched. In addition, the third warp is also used to stretch the second warp. At the same time, the difference in the length of the thread foot is decreased, because the behavior functions in a braking manner with respect to the extension of the energy absorbing belt 1, and therefore the extension of the belt becomes further gentle.

  On the other hand, in the conventional energy absorbing belt including Patent Document 3, since the woven structure is a knit or twill weave, there are many warp floats, and the core yarn is floating along the longitudinal direction of the fabric. The warp or the core yarn is not uniformly cut but concentrated at a predetermined portion, so that the amplitude of the above-described impact load waveform is large and long.

  In the present invention, the bulging portion formed by the second and third warps at the end portion of the impact load waveform is hardly seen when the drop load is 85 kg or 100 kg. However, when the load is 120 kg or more, as shown in FIGS. 8 and 9, it appears on the graph.

  In addition, the size of the bulging portion increases as the drop load increases, but the shape of the bulging portion is an extremely gentle curve that is inevitably generated from the configuration of the present invention. As a result, at the end of the impact load waveform, the object is not subjected to strong impact as in the conventional example, and the safety of the object is reliably ensured. It is.

  In any case, in the present invention, within a predetermined period immediately after the impact load is applied, it falls below the “safety band standard” of 8.0 kN, and the impact load value level is surely soft. The energy can be absorbed, and the energy absorbing belt can be cut and protected from being dropped without fail.

  On the other hand, in Patent Document 3, in addition to the above-described problems, there is no mechanism that allows the energy absorbing belt to be further extended after all the core yarns have been cut. Since a steep bulge is formed at the end of the impact load waveform, the energy absorbing belt is not reliably cut and is not guaranteed to safely stop and protect the object from falling.

  6 to 8 showing the impact load waveform of the energy absorbing belt of Patent Document 3 are shown in FIG. 6 to FIG. 8, that the weave structure is obtained from a twill weave. The impact load waveform of the energy absorbing belt using a plain woven fabric in No. 3 is shown in FIG. 9 described in the Patent Document 3 showing the impact load waveform in the Patent Document 3, as shown in FIG. It is clear that the impact load waveform of the invention is similar but not similar.

  Furthermore, in this invention, in order to examine the difference in the characteristics of the energy absorbing belt when the first warp is not used and the energy absorbing belt when the first warp is used, Table 2 shows. In the same manner, the number of used first and second warp yarns was changed from 0 to 24 while fixing the number of used second and third warp yarns to the value of the above-described specific example. In Table 2, samples Nos. 1 to 5 are shown in Table 2, and the number of applied first warps is fixed to 24 as described above. Table 2 shows the results of measurement with the sample numbers 6 to 8 being changed to 140 kg.

14A to 14E show the impact load waveforms for the above materials. The time axis of each impact load waveform is set to be the same as the time axes of the waveform diagrams of FIGS. It is.
As is clear from the above experimental results, in the energy absorbing belt (sample number 1) that does not use the first warp, as shown in FIG. 14 (A), the belt continues to stretch for a long time, Thereby, the elongation of the whole belt becomes large, and it becomes clear that the energy absorbing belt without the first warp is not practical.

  Furthermore, in the sample of Sample No. 1 that does not include the first warp, since the belt continues to stretch for a long time, the total amount of energy received by the falling operator increases, and the operator feels uncomfortable. There is a possibility of feeling strong or in some cases suffering obstacles.

  On the other hand, in the energy absorption belts of the sample numbers 2 to 5 using the first warp, the impact load is obtained by combining the second to third warps and the first warp. Although the maximum impact load increases as the first number of warps increases, the ideal impact load is maintained at an ideal value of 4.5 kN or less, and from FIGS. 14 (B) to 14 (E). As can be seen, it has been found that the time during which the belt is stretched is greatly reduced, and at the same time, the stretch of the belt is reliably suppressed.

  This is because the energy absorbing belt according to the present invention forms a small amplitude energy absorbing region immediately after the dropping impact is applied, and accepts the falling worker through the restrained elongation. Since it has a configuration that absorbs energy and finishes stretching in a short time, the total amount of energy received by the worker is also suppressed. The risk of receiving it is definitely avoided.

  However, in the present invention, even when the drop load is set to 140 kg by combining the first warp, the impact load remains below the regulation value of 8 kg, and the overall elongation is reduced. It is possible to keep the value less than the regulation value of 650 mm.

  That is, in the present invention, by adjusting the number of the first warps, the impact load and the amount of elongation of the belt can be adjusted to appropriate values. There is an advantage that the characteristic can be set to an appropriate value according to the intended use, and at the same time, a large degree of freedom is secured in setting the specification for obtaining the characteristic.

  Furthermore, in the present invention, as a result of studying the relationship between the number of used first warps 4-1 and the number of used second warps 4-2, the unit of the second warps 4-2 was determined. It has been found that it is desirable that the number of the first warp yarns 4-1 used is 13 to 20% of the number used per unit.

  Next, in order to examine the static characteristics of the energy absorbing belt 1 of the present invention manufactured according to the above-mentioned fabric specifications, the tensile strength and elongation of each of the energy absorbing belts 1 were measured, and the results are shown in FIG. Show.

  As can be understood from FIG. 2, the energy absorption belt 1 according to the present invention has a waveform different from the tensile strength / elongation curve exhibited by the conventional energy absorption belt, and the energy absorption belt according to the present invention. The belt 1 shows a gentle ascending curve in which the variation of the load (strength) with respect to the elongation is almost flat.

  Here, FIG. 10 and FIG. 11 showing the dynamic impact load waveform of the energy absorbing belt according to the present invention again and FIG. 12 and FIG. 13 showing the dynamic impact load waveform of the energy absorbing belt of Patent Document 3 are compared and examined again. In that case, in Patent Document 3, since all the cut yarns are cut, the period during the energy absorption period is long and the amplitude is large, but in the present invention, the cut yarns are stretched with respect to the highly stretchable yarns. Since the condition of cutting while applying the brake is exhibited, the period is short and the amplitude is small. As a result, as shown in FIG. In contrast to an ideal curve that rises gently to the right, in Patent Document 3, as shown in FIG. 5 (C), during the energy absorption period, a considerably large amplitude oscillation is observed, and the graph during the period is Shows a substantially flat state

  On the other hand, if FIG. 5 (A) and FIG. 5 (B) showing the static characteristic waveforms of Patent Documents 1 and 2 are examined, FIG. 5 (A) and FIG. 5 (B) showing both static characteristic waveforms. 5 and the static characteristic waveform of Patent Document 3 shown in FIG. 5C, it is clear that both are similar to the static characteristic waveform of Patent Document 3.

Therefore, the dynamic characteristic waveforms of Patent Documents 1 and 2 are estimated to be the same as the dynamic characteristic waveform of Patent Document 3.
Therefore, the energy absorption belts of Patent Documents 1 and 2 are considered to have static and dynamic characteristics different from those of the present invention.

Table 1 shows the configuration specifications of each energy absorbing belt used in the above comparative experiment.
The energy absorbing belt 1 according to the present invention was designed so that the number of wefts to be driven was 17 picks / 30 mm, the thickness was 6.84 mm, the width was 20.8 mm, and the weight was 77.42 g / m.

  Next, when referring to the relationship between the first warp and the second warp in the present invention, the first warp in the present invention includes three types of warps used in the present invention. Among them, it is desirable that the yarn has the lowest elongation characteristic, and it is preferable that the yarn is gradually cut while the second warp is being stretched.

On the other hand, when the impact load is applied, the second warp yarn needs to be stretched to absorb the impact energy, and is desirably a yarn having a relatively high stretch rate.
That is, it is desirable that the second warp has the largest elongation characteristic among the three types of warp, and therefore has a high elongation rate.

  As already described, in the energy absorbing belt 1 according to the present invention, when an impact load is applied, the second warp is mainly stretched, so that a considerable impact energy is applied. The first warp is gradually cut according to the extension of the second warp, thereby suppressing the rapid extension of the second warp and stabilizing the first warp. In addition, the shock absorbing elongation of the energy absorbing belt that is uniform can be realized.

In the present invention, in order to realize such a configuration, the stretch rate of the second warp needs to be 80% or more.
That is, in the static tensile test of the energy absorbing belt, the breaking elongation of the energy absorbing belt is set to about 80 to 95%, and if judged from such criteria, the energy absorbing belt is at least This is because the second warp does not break and needs to maintain the extensibility until the belt breaks.

  Therefore, the stretch rate of the second warp in the present invention is desirably 80% or more, more preferably, the stretch rate of the second warp is 100% or more, and more ideally, It is desirable that it is 140% or more.

  Here, in order to examine the relationship between the first and second warp yarns described above in the present invention, in the specific example described above, the first warp yarn has an elongation rate of 50%. , And two samples of the case where the first warp is not used and the case where 24 pieces of the first warp are used are prepared, and a load of 85 kg is used using the same test apparatus as described above. The impact drop test was conducted.

The results of the test are shown in FIGS. 15A and 15B, respectively.
That is, FIG. 15A is an impact load waveform showing a test result of an energy absorption belt composed of the second and third warps and wefts without using the first warp. B) is an impact load waveform of an energy absorbing belt woven with the first and third warps using 24 first warps.

As can be understood from the results of both tests, in the sample without the first warp, the belt suddenly increased in impact load in a very short time and reached a break in a short time.
On the other hand, when the first warp is used in combination, the impact load waveform has a short cycle as described above, and at the same time, the impact load is increased as compared with the case where the first warp is not used.

  This means that the elongation rate of the second warp is low and breakage occurs before reaching the elongation of 80% in the test of the energy absorbing belt, and the energy of the first warp is As a result of being added to the waveform of the second warp, it is estimated that the impact load is increasing.

  Such a decrease is that the second warp needs to have at least an elongation rate of 80% or more, and in the present invention, the second warp mainly has a function of absorbing the impact energy. The unwarped first warp indicates that the second warp has a function of suppressing the extension of the second warp, and consequently the rapid extension of the energy absorbing belt.

  In addition, when the characteristics of the present invention are compared with a nylon triple-strike (or eight-strike) rope used as a lifeline part (hereinafter referred to as a lanyard part) of a conventionally known safety belt for work at high places, As shown in FIGS. 16 (A) and 16 (B), the impact load waveform of the energy absorbing belt according to the present invention is such that the nylon rope has a maximum impact load of 8.0 kN. The energy absorbing belt is 4.5 kN, and it is clear that the shock absorbing ability is extremely large.

Furthermore, as is clear from FIG. 16 (A), the impact load waveform shows a sudden rise and fall in a very short time, so the load on the fall object is instantaneously very large. This indicates that there is an extremely high risk of damage to the
On the other hand, in the present invention, as shown in FIG. 16B, the energy absorption period is long, and the impact load is set to a level much lower than the level that damages the fall target.

  The present invention can be effectively used as an energy absorbing belt.

1: Energy absorption belt 2: First fabric 3: Second fabric 4: Warp yarn 4-1: First warp yarn 4-2: Second warp yarn 4-3: Third warp yarn 5: Weft yarn 6: Yarn Feet 7: Tangle 40: Drop impact test device 41: Shaft 48: Control measuring means 42: Load cell 43, 44: Chuck part 46: Weight 45: Energy absorption belt 47: Stopper

Claims (3)

An energy absorbing belt, which is composed of a first fabric and a second fabric, which are arranged in two layers on the front and back sides and are connected to each other by a leash thread. Each of the fabrics has a plain weave structure, and each of the fabrics is woven with at least three types of warp yarns and at least one type of weft yarns having different elongation characteristics and breaking strength, and at least one type of warp yarns. Is a high elongation yarn having a breaking elongation of 100% or more, and the other warp yarns are composed of chopped yarns having a breaking elongation of 35% or less, and when the belt impact load is applied, An energy absorbing belt characterized by continuing to absorb energy by continuously stretching the high elongation yarn even after energy absorption by breaking. 2. The energy absorbing belt according to claim 1, wherein the number of cut yarns used in the warp yarns is set to a ratio of 13 to 20% with respect to the number of high elongation yarns used. Energy absorbing belt according to claim 1 or 2 also core yarn to both or intermediate portion thereof of this first and second fabric, characterized in that it is not in use.

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