JP6200117B1 - Wind and snow fence - Google Patents

Abstract

A windproof snow fence that can effectively eliminate slack generated in a windproof net without relying on a connection device. A windproof net 30 having improved shape restoring property and a connecting device not including a spring are used in combination, and the windproof net 30 imparts shape restoring property to a woven / knitted sheet 35 and a woven / knitted sheet 35. The covering resin 36a and the inner resin 36b filled in the entire through gap of the entangled yarn / main yarn crossing portion, so that the windproof net 30 can be restored to its original shape by the self-restoring force. The amount of elastic deflection deformation in the internal resin 36 in the pulling direction is related to the amount of elongation deformation of the woven or knitted sheet 35. [Selection] Figure 3A

Description

  The present invention relates to a windproof snow fence provided with a windproof net, and more particularly to a windproof snow fence that prevents slack with the self-deflection restoring force of the net body even when the windproof net is deformed.

Various windbreak fences and snowbreak fences in which a flexible windbreak net is stretched between adjacent struts have been proposed (Patent Document 1).
As a means to fix the side edge of the windbreak net to the column, a plurality of support bolts are attached to the column side, while a plurality of bolt holes are opened at the side edge of the windbreak net, and the support bolts are passed through the bolt holes of the windbreak net. Inserting and fixing is a common attachment method.
Conventional windproof nets stretched between struts in this way have problems such as loosening due to plastic deformation and durability such as the fixed portion of the windproof net being damaged due to repeated deflection. It was.
In Patent Document 2, one side of a windproof net is fixed to one end of a plurality of guide bolts penetrating through a support column, and the windproofing is performed using the spring force of a spring member that is contracted to the other end of each guide bolt. It is disclosed to prevent the slack of the net.

JP 2010-216095 A JP 2004-316403 A

The conventional wind fence or snow fence has the following problems to be improved.
<1> In the form in which the windproof net is directly attached to the support column, the windproof net is easily slackened due to creep deformation.
<2> To that end, it is necessary to regularly check the slack of the windproof net visually, and when the slack becomes excessive, maintenance work such as re-tensioning the windproof net by tightening the bolts must be performed.
<3> In a windproof net mounting structure in which a support bolt is inserted and fixed in a bolt hole opened at a side end portion of the windproof net, the entire net cannot be evenly tensioned, and a horizontal wrinkle is likely to occur in the windproof net.
<4> A connection device including a plurality of spring members described in Patent Document 2 is provided with respect to the upper and lower portions of one intermediate strut in order to support the four left and right portions of the windproof net between adjacent intermediate struts. At least four guide bolts and four sets of spring members are required.
As described above, the connection device including a plurality of spring members has a problem that a lot of time and labor are required for the installation work of the windproof net in addition to the problem that the number of components is large and the cost is high.

The present invention has been made in view of the above points, and an object of the present invention is to provide a windproof snow fence that can effectively eliminate slack generated in the windproof net without relying on a connection device.
Furthermore, the other object of this invention is to provide the wind-proof snow fence which can be attached to a support | pillar without damaging a wind-proof net via the connection apparatus which does not comprise a spring member.

TECHNICAL FIELD The present invention relates to a windproof and snowproof fence in which a windproof net with improved shape restoring properties and a connecting device not including a spring are used to stretch a windproof net between adjacent columns.
The windbreak net is composed of a woven or knitted sheet made of entangled woven fabric in which a through gap is formed at the intersection of the entangled yarn and the main yarn, and a resin that imparts shape restoring property to the woven or knitted sheet.
The resin is composed of a covering resin that covers the outer circumferential surface of the entangled yarn and the main yarn, and an internal resin that is filled in the entire through gap at the intersection of the entangled yarn and the main yarn.
In order for the windproof net to be restored to its original shape by self-restoring force, the amount of elastic deflection in the tensile direction of the coating resin and the internal resin is related more than the amount of elongation deformation of the woven or knitted sheet.
When the windbreak net deforms flexibly, the resin (coating resin and internal resin) elastically deforms in the net pulling direction and compressively deforms in the net thickness direction. Deflection restoring force of tension toward the net and compression toward the thickness direction of the net is accumulated. When the wind load is unloaded, the windproof net is restored to the tensioned state before the deformation by the deflection restoring force in two directions accumulated in the resin.
When a windproof net is stretched between adjacent struts, the entangled thread is stretched so as to be positioned in the direction in which the windproof net is stretched.
The coupling device that does not include a spring includes a plurality of support bolts, a vertical frame member that is slidably passed through and supported by the plurality of support bolts, and a grip column that has a C-shaped cross section attached to a side surface of the vertical frame member And a locking bar that can be inserted and locked into the slit-containing receiving hole of the grip column, and an outer peripheral surface of the locking bar around which the both ends of the windproof net are wound, and the locking bar The both ends of the windproof net are clamped over the entire length between the inner peripheral surface of the accommodation hole of the inserted grip pillar.
By tightening a plurality of fixing bolts screwed to a part of the grip column, the side end portion of the windproof net is clamped between the locking bar and the peripheral surface of the grip column.
The grip column may be attached to the side surface of the vertical frame member so as to be slidable along the vertical direction, or may be attached so as not to slide.
An acrylic emulsion resin (acrylic resin) is suitable for the coating resin and the internal resin constituting the resin, and a cheap and high-strength chemical fiber (polyester fiber) is suitable for the woven or knitted sheet.

The present invention can obtain at least one of the following effects.
<1> Since the windproof net is formed by attaching resin to the woven or knitted sheet so as to increase the flexural restoring force of the windproof net, even if the windproof net is stretched and deformed, the windproof net itself is the original tension after unloading. The shape is gradually restored to the installed state and no creep remains on the windbreak net.
For this reason, it is possible to effectively eliminate the slack generated in the windproof net without depending on the connection device.
<2> After installing a windbreak net between adjacent struts, maintenance such as checking for slack and re-tensioning of the windbreak net is unnecessary. The labor and cost required for maintenance can be greatly reduced.
<3> Since the windproof net has a shape restoring property, a plurality of spring members that have been incorporated in the connection device until now can be omitted, and the connection device can be simplified and the cost can be reduced.
<4> By using a pinching type connecting device that can hold both ends of the windproof net over the entire length, the windproof net can be applied with equal tension between adjacent struts without opening bolt holes in the windproof net. Can be stretched.
<5> The windproof net has several times higher resilience of the entangled yarn than the main yarn, so the tangled yarn is stretched in the net tensioning direction to suppress the deformation of the windproof net in the height direction. However, the shape restoring property of the windproof net can be maximized.
<6> When the grip column is slidable with respect to the vertical frame member, the windproof net can be stretched without being affected by the height difference even if there is a height difference between adjacent columns.

Partial perspective view of a windproof snow fence with a windbreak net Enlarged view of a windproof net with part broken FIG. 3 is a cross-sectional view taken along line III-III in FIG. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2, showing an enlarged cross-sectional view of the windproof net during deformation Horizontal cross-sectional view of windproof net and support attachment Schematic diagram of loading test of specimen Schematic diagram of loading test of test specimen during loading Explanatory drawing of measurement result of deflection amount of windbreak net Explanatory drawing of measurement result of deflection amount of contrast windproof net Explanatory drawing of measurement result of deflection recovery amount of windbreak net Explanatory drawing of measurement result of deflection recovery amount of contrast windproof net Comparison explanatory diagram of deflection restoration amount of windbreak net and contrast windbreak net Explanatory drawing of test results of elastic hysteresis test (entangled yarn direction) of windproof net Explanatory drawing of test results of elastic hysteresis test (main yarn direction) of windproof net Comparison explanatory diagram of the test results of the second test of the entangled yarn direction and the first test of the main yarn direction

  The windproof snow fence according to the present invention will be described below with reference to the drawings.

1. Windproof and snow fence configuration

<1> Outline of Wind-Proof and Snow-Proof Fences Referring to FIG. 1, the wind- and snow-preventive fence assumed by the present invention includes a plurality of struts 10 erected at a predetermined interval and springs between adjacent struts 10. And a plurality of windproof nets 30 stretched through a connecting device 20 that is not connected, and can be applied to a windproof fence or a snowproof fence alone.
The struts 10 are, for example, steel materials such as H-shaped steel and box steel, concrete, a composite structure material of concrete and steel, and the upper interval holding member 11 laid across the upper portions of the adjacent struts 10 keeps the interval between the struts 10 constant. Hold.

<2> Windproof Net Referring to FIGS. 2 and 3, the windproof net 30 is a main yarn 32 that is a weft between the entangled yarns 31, 31 while the two tangled yarns 31, 31 that are warps are entangled with each other. Woven and knitted sheet 35 woven into a square mesh 33a and covering the entire circumferential surface of both yarns 31 and 32, and in a through gap 34 formed at the intersection of both yarns 31 and 32 And the resin 36 filled in.
The opening ratio of the windproof net 30 covered with the resin 36 is desirably in the range of 30% to 60% (wind shielding ratio 70% to 40%), and most desirably the opening ratio 40% (wind shielding ratio 60%).
The reason why the opening ratio of the windproof net 30 is set to 40% or more is to make it difficult for wind turbulence to occur on the leeward side of the windproof net 30 while maintaining good viewability (visibility) of the windproof net 30. .

<2.1> Woven Knitted Sheet The woven / knitted sheet 35 is a loosely knitted flexible mesh-like knitted fabric, and has a substantially triangular shape on both sides of the main yarn 32 intersecting with the entangled yarns 31, 31. Through gaps 34, 34 are formed.
In this example, the weight of the main yarn 32 and the two entangled yarns 31, 31 per unit length is substantially equal, but the weight of one entangled yarn 31 is shown to be a half of the main yarn 32. The weights of the entangled yarns 31, 31 and the main yarn 32 can be changed as appropriate.

As a means for imparting elasticity to the windproof net 30, it is possible to use an elastic material for the knitting yarn of the woven or knitted sheet 35 itself and to knit it as an elastic knitted fabric structure. Cost is not suitable for practical use.
Therefore, in the present invention, an inexpensive knitted knitted fabric is used for the woven / knitted sheet 35, and the wind-breaking net 30 is positively filled with resin in the through gaps 34, 34 of the woven / knitted sheet 35 as described later. Added elasticity.

<2.2> Direction of Yarn When the windproof net 30 is stretched between the struts 10, the entangled yarns 31, 31 are positioned in the tensioning direction (lateral direction) of the windproof net 30, and the main yarn 32 is positioned in the windproof net 30. It is used by being positioned in a direction orthogonal to the tensioning direction (vertical direction).
Using the entangled yarns 31, 31 of the windproof net 30 in the horizontal direction and the main thread 32 in the vertical direction makes it possible to reduce the amount of deformation in the height direction of the windproof net 30 while reducing the shape restoring property of the windproof net 30. This is to make the most of it.

<2.3> Material of Woven Knitted Sheet The tangled yarn 31 and the main yarn 32 constituting the woven / knitted sheet 35 are knitted with high-strength fibers excellent in corrosion resistance, weather resistance, and durability. For example, polyester fibers Multifilaments (flat yarn or twisted yarn) of fibers such as polyethylene fibers and aramid fibers, or monofilaments can be used. Polyester fibers are practical from the viewpoint of tensile strength and economy.

<2.4> Resin The resin 36 is a resin whose main purpose is to impart a bending restoring force to the woven or knitted sheet 35, and covers the outer circumferential surfaces of the tangled yarns 31 and 31 and the main yarn 32 of the woven and knitted sheet 35. The coating resin 36 a and the internal resin 36 b filled in the entire through gap 34 formed at the intersection of the entangled yarns 31, 31 and the main yarn 32.
The internal resin 36b and the coating resin 36a are continuous and systematically integrated, and have a structure in which the rigidity of the woven / knitted sheet 35 is increased.
The reason why the internal resin 36 b is inserted in the through gap 34 is to increase the bending restoring force at the intersection of the entangled yarns 31, 31 and the main yarn 32.

<2.4.1> Resin material As the coating resin 36a and the internal resin 36b constituting the resin 36, an acrylic emulsion resin excellent in corrosion resistance, weather resistance, and durability can be used, and an acrylic resin is suitable for practical use. It is.

<2.4.2> Example of resin adhesion As a means for attaching the resin 36 (the coating resin 36a and the internal resin 36b) to the entire area of the woven or knitted sheet 35, for example, the relaxed woven or knitted sheet 35 is uncured (melted). For example, a method of immersing (so-called soaking) in a resin solution in a state) or a method of spraying a resin solution on a woven or knitted sheet 35 in a relaxed state can be used.
The reason why the resin is adhered to the woven or knitted sheet 35 in a relaxed state is that the narrow gap 34 is widened to facilitate the penetration of the internal resin 36b, and the covering resin 36a and a part of the internal resin 36b are entangled with the yarn 31. , 31 and the main yarn 32 are impregnated not only into the surface but also into the interior to enhance the adhesion between the woven / knitted sheet 35 and the resin 36.

<2.5> Relationship between Elongation of Woven Knitted Sheet and Resin The amount of elastic deflection deformation of the covering resin 36a and the inner resin 36b in the tensile direction is larger than the amount of elongation deformation of the woven / knitted sheet 35 in the tensile direction. There is a relationship.
That is, even if the woven / knitted sheet 35 reaches the limit of elongation deformation due to tension, the elongation of the woven / knitted sheet 35 and the resin 36 does not reach the elastic limit due to tension of the resin 36 (the coating resin 36a and the internal resin 36b). It is related.

<3> Connecting Device In this example, as a means for attaching both end portions of the windproof net 30 to the support column 10, a clamping type connecting device 20 that does not include a spring is used.
The connecting device 20 illustrated in FIG. 4 will be described. The connecting device 20 includes a plurality of support bolts 11 protruding in the horizontal direction on the side surface of the support column 10, and slidably penetrates the plurality of support bolts 11 to be parallel to the support column 10. The vertical frame member 21 disposed on the side of the vertical frame member 21, the grip column 25 having a C-shaped cross section attached to the side surface of the vertical frame member 21, and the locking rod that can be inserted and locked in the accommodation hole 26 with the slit of the grip column 25. 27.
Ends of the left and right sides of the windproof net 30 are wound around the locking rod 27, and the left and right ends of the windproof net 30 together with the locking rod 27 are inserted into the accommodation holes 26 of the grip column 25. The windproof net 30 is fixed so that it cannot be pulled out in the direction of tension.

<3.1> Support Bolt The support bolt 11 is fixed to the side surface of the column 10 by a fixing nut 12 or welding.
When the support column 10 is made of H-shaped steel, the support bolt 11 made of both screw bolts can be passed through the web, and a pair of fixing nuts 12 can be fastened and fixed from both sides.
The support bolts 11 may be provided in a plurality of locations (two or more locations) at intervals in the height direction of the support column 10 according to the mounting height of the windproof net 30.

<3.2> Vertical Frame Material A vertical frame material 21 having a length substantially the same as the height of the windproof net 30 is attached to the side of the support column 10 so as to be slidable along the extending direction of the windproof net 30.
The vertical frame material 21 is a rigid material capable of supporting the tension of the windproof net 30 and is formed of a metal such as aluminum or a hard resin.
A plurality of through holes 22 are formed in the vertical frame member 21 in accordance with the mounting height of the support bolt 11, and an adjustment nut 13 is screwed to the tip of the support bolt 11 inserted through the through hole 22. The locking position of the vertical frame member 21 with respect to the support bolt 11 can be adjusted by rotating the adjustment nut 13.

<3.3> Grip Column A grip column 25 having substantially the same overall length as the vertical frame member 21 is attached to one side surface of the vertical frame member 21.
The grip column 25 is a holding member that functions to hold the windproof net 30 in cooperation with the locking rod 27, and is formed of a metal such as aluminum, a hard resin, or the like.
The grip column 25 has a receiving hole 26 having a C-shaped cross section over its entire length. A narrow slit 28 communicating with the accommodation hole 26 is formed in a part of the accommodation hole 26.

In this example, the grip column 25 is slidably anchored in the vertical direction with respect to the vertical frame member 21 by a fitting locking mechanism formed on one side surface of the vertical frame member 21 and the opposing surface of the grip column 25. As shown, the grip column 25 may be slidably attached to the vertical frame member 21, or the vertical frame member 21 and the grip column 25 may be formed integrally.
When the grip column 25 is moored slidably with respect to the vertical frame member 21 in the vertical direction, the mounting height of the grip column 25 can be arbitrarily set without being affected by the mounting height of the support bolt 11 and the vertical frame member 21. Can be changed.
In other words, even if there is a height difference between a pair of adjacent columns 10, the windproof net 30 can be stretched without being affected by the height difference.

<3.4> Clamping Structure with Grip Column and Locking Rod Although the locking rod 27 can be inserted into the receiving hole 26, it has a dimensional relationship that can restrict the outside through the slit 28.
The reason why the grip column 25 and the locking rod 27 are combined is that the side end of the windproof net 30 is sandwiched and fixed over the entire length without opening a bolt hole in the windproof net 30.
Reference numeral 29 denotes a fixing bolt screwed into a part of the grip column 25, and can press the locking rod 27 in the accommodation hole 26 toward the slit 28 side.
The locking rod 27 wound around the side end of the windproof net 30 is pressed against the slit 28 via the fixing bolt 29, and the windproof net 30 is interposed between the outer peripheral surface of the locking rod 27 and the inner peripheral surface of the accommodation hole 26. By sandwiching the side end portions of the windproof net 30, the side end portions of the windproof net 30 can be connected to the grip column 25 in a non-separable manner over the entire length.

2. Winding Net Tensioning Method A method of stretching the windproof net 30 between adjacent struts 10 using the connecting device 20 will be described with reference to FIG.

<1> Connection of Windproof Net and Grip Column The side end portion of the windproof net 30 is wound around the locking rod 27, and the side end portion of the windproof net 30 together with the locking rod 27 is inserted into the accommodation hole 26 of the grip column 25. .
By tightening the fixing bolt 29, the side end portion of the wind-proof net 30 can be clamped across the entire length by the frictional force between the inner peripheral surface of the accommodation hole 26 and the outer peripheral surface of the locking rod 27.

<2> Temporary fixing of windproof net Support bolts 11 are attached in advance to a plurality of locations (for example, two locations on the top and bottom) of the side surface of the support column 10.
A vertical frame member 21 is integrally attached to one side of the grip column 25, and after fitting a through hole 22 of the vertical frame member 21 into the support bolt 11, an adjustment nut 13 is screwed to the tip of the support bolt 11. Thus, the vertical frame member 21 is temporarily fixed so as not to come out of the support bolt 11.
The vertical frame members 21 are respectively attached to the left and right side end portions of the windproof net 30, and the left and right vertical frame members 21 are temporarily fixed to the support bolts 11 provided at the four upper and lower portions of the adjacent columns 10.

<3> Tensioning operation of windproof net When the adjustment nut 13 is rotated and the vertical frame member 21 is pulled in the approaching direction of the support column 10, the grip column 25 and the locking rod 27 integral with the vertical frame member 21 become the vertical frame member. 21 slide movement is followed.
By uniformly tensioning the left and right side end portions of the windproof net 30 as described above, uniform tension can be applied to the entire windproof net 30 temporarily fixed between the adjacent struts 10.
As a connecting means between the windproof and snow fence post 10 and the windproof net 30, by using the clamping type coupling device 20 in which the grip column 25 and the locking rod 27 are combined, a bolt hole is not formed in the windproof net 30. The entire windproof net 30 can be tensioned with equal force.
By using the pinching type connecting device 20, the mesh structure of the windproof net 30 can be stretched without giving distortion or local elongation.

3. The wind-reducing action of the wind-proof net The long-term stable wind-reducing action by the wind-proof net 30 stretched between the adjacent struts 10 is well-known and will not be described in detail.

4). The shape restoring action of the windbreak net 30 The shape restoring action of the windproof net 30 will be described with reference to FIG.

<1> Deflection deformation of windproof net When wind load acts on the windproof net 30 stretched between adjacent struts 10, the windproof net 30 is bent and deformed to the leeward side.
Since the entangled yarns 31, 31 of the windbreak net 30 are stretched in the tensioning direction (lateral direction) of the windbreak net 30, the entangled yarn 31, The deflection amount of 31 is outstanding.

The windproof net 30 used in the present invention is composed of a knitted fabric of woven fabric in which the woven / knitted sheet 35 is knitted by weaving the main yarn 32 between the entangled yarns 31, 31 while the two entangled yarns 31, 31 are entangled with each other. In addition, the resin 36 that covers the woven or knitted sheet 35 also has a penetration formed at the intersection of the two yarns 31 and 32 in addition to coating the entire circumferential surfaces of the two yarns 31 and 32 with the coating resin 36a. The gap 34 is filled with an internal resin 36b.
Therefore, since the shape of the windproof net 30 deformed by wind load is restored to the original stretched state as described below after unloading, the durability of the windproof net 30 itself is improved over a long period of time. Maintenance characteristics are improved.

<2> Shape restoration mechanism of windproof net When the windproof net 30 is flexibly deformed, the coating resin 36a and the internal resin 36b are elastically deformed in the net pulling direction and are also compressed in the thickness direction of the net. To do.
Since the amount of elastic deflection deformation of the covering resin 36a and the inner resin 36b in the tensile direction is larger than the amount of deformation of the woven / knitted sheet 35 in the tensile direction, the deflection deformation of the woven / knitted sheet 35 reaches the maximum. However, the coating resin 36a and the internal resin 36b do not reach the elastic limit.
When the woven or knitted sheet 35 is bent and deformed, a bending restoring force (internal stress) in two directions of tension in the net direction and compression in the thickness direction of the net is applied to the coating resin 36a and the inner resin 36b. Accumulated.
When the wind load of the windproof net 30 is unloaded, the internal stress in the two directions accumulated in the coating resin 36a and the internal resin 36b acts as a bending restoring force. Restore state.
That is, when the wind load is unloaded, the coating resin 36a and the internal resin 36b are contracted and deformed in the net direction and are expanded and deformed in the net thickness direction.
The “deflection restoring force” in the present invention is not an elastic force that restores instantaneously, but a restoring force characteristic that gradually restores shape and elongation over several hours immediately after unloading.

5). Windproof Net Restorability Test In order to confirm the flexural resilience of the windproof net 30, the following verification tests were performed.

<1> Verification of Deflection of Windproof Net The amount of deflection after applying a wind load to the windproof net 30 obtained by coating a polyester fiber fabric with an acrylic resin and the amount of flexure restoration after unloading were measured.

[Test method]
a. Test Body FIG. 5A shows a schematic diagram of a windproof net loading test, and FIG. 5B shows a test schematic diagram in which deflection occurs in the windproof net during loading.
The windproof net of the test body is composed of a windproof net 30 in which the entangled yarn is positioned in the net tension direction, and a comparison windproof net (in contrast to the windproof net) in which the main yarn is positioned in the net tension direction. Types were prepared, and each net was stretched with the same tension between a pair of horizontal support columns 10.
Both net sizes are 1000 mm × 420 mm.
The windproof net has a mass of 440 g / m ² or more, a mesh size of 1.8 mm, an aperture ratio of 40% (wind shield ratio of 60%), and a design standard strength of 40 kN / m.

b. Wind load (load)
Assuming a harsh situation where the wind of 66.5m / s in the wind continues to hit the net for 24 hours, the wind load of the design wind speed of 66.5m / s (approximately 2415N / m ² ) is directly above the two types of test specimens. A corresponding weight (flat steel W) was applied to the upper surface of the net for 24 hours, and the amount of deflection of the windproof net was measured every hour.
Thereafter, the flat steel W was unloaded, the amount of deflection every hour was measured, and finally the amount of deflection after 24 hours of unloading was measured.
The amount of deflection was measured in mm using a microlaser sensor.

[Test results]
a. The results were read every 1 hour for deflection amount of change of the windbreak net 30 where the deflection of entanglement yarn windbreak net is positioned toward the tensioning direction of the net shown in Fig.
It was confirmed that the windproof net 30 creeped from about 45 mm at the start to about 51 mm over the course of 24 hours.

Next, the flat steel W of the windproof net 30 was unloaded, and the 24-hour deflection restoration was measured.
FIG. 7 shows the results of changes with time read every hour after unloading.
In the windproof net 30 in which the entangled yarn was positioned in the net tension direction, the deflection was restored 4 hours after unloading, and the original shape was maintained after 24 hours.

b. The results were read every 1 hour for deflection amount of change in the contrast windbreak net deflection of main yarn contrasting windbreak net is positioned toward the tensioning direction of the net shown in Fig.
It was confirmed that the windshield net creeped from about 51 mm at the start to about 66 mm over the course of 24 hours.
Next, the flat steel W of the comparative windproof net was unloaded and 24 hour deflection recovery was measured.
FIG. 9 shows the results of changes over time read every hour after unloading.
After unloading, it was confirmed that it was restored to about 18 mm in about 5 hours from about 26 mm, but it was not completely restored like the windproof net 30.

c. FIG. 10 shows a change with time after unloading of the flat bar W in the comparative windproof net 30 and the comparative windproof net for flexure restoration .
In the windproof net 30, the deflection was completely restored in 3 to 4 hours after unloading, whereas in the comparative windshield net, the deflection remained without being completely restored.
From this result, it was confirmed that the deflection restoring property of the windproof net 30 in which the entangled yarn was positioned in the net tension direction and the phenomenon in the comparative windproof net in which the main yarn was positioned in the net tension direction.

<2> Elastic Hysteresis Test The elastic hysteresis test evaluates rigidity by repeatedly applying a load with a tensile tester and confirming how much strain remains after the addition.
In the above-described deflection restoration verification test, evaluation with repeated loads could not be performed. Similarly, an elastic hysteresis test was performed in two directions (entangled yarn direction and main yarn direction) on two types of test bodies.

[Test method]
The test specimen had a net size of 200 mm × 100 mm, and was performed three times each in the entangled yarn direction and the main yarn direction.
The tensile speed was 1 mm / min, and the number of repetitions was 10 assuming an abnormal number of windbreaks encountered within the installation period of the windbreak and snow fence.
Strain was measured by measuring displacement using a digital camera.
Further, the maximum load was calculated from a deflection restoration verification test in order to obtain a constant tension since the fineness differs between the entangled yarn and the main yarn. The maximum value was 600 N for the entangled yarn and 450 N for the main yarn.

[Test results]
FIG. 11 shows the test results in the entangled yarn direction, and FIG. 12 shows the test results in the main yarn direction.
The mean weaving direction was 0.12% strain, while the main yarn direction was 0.39% strain.
FIG. 13 shows a comparison between the second test in the entangled yarn direction and the first test in the main yarn direction.
From these comparisons, it was confirmed that the entangled yarn direction has a higher deflection restoring force about three times than the main yarn direction.

DESCRIPTION OF SYMBOLS 10 ... Support | pillar 11 ... Support bolt 13 ... Adjustment nut 20 ... Connecting device 30 ... Windproof net 31 ... Tangle 32 ... ... Main yarns 33a, 33b ... Mesh 35 ... Woven sheet 36 ... Resin 36a ... Coating resin 36b ... Internal resin

Claims (7)

A wind and snow fence in which both ends of the windproof net are stretched through a coupling device that does not include a spring between a plurality of columns,
A woven or knitted sheet made of entangled woven fabric in which the windproof net has a mesh shape;
It consists of a resin that imparts shape restoring properties to the woven or knitted sheet,
A through gap is formed at the intersection of the entangled yarn and the main yarn of the woven or knitted sheet,
A coating resin in which the resin is attached to the outer circumferential surface of the entangled yarn and the main yarn;
It is formed integrally with the coating resin, and consists of an internal resin that is filled and adhered to the entire through gap of the crossing portion of the entangled yarn and the main yarn,
The amount of elastic deflection in the tensile direction of the coating resin and internal resin is greater than the amount of elongation deformation of the woven or knitted sheet so that the windbreak net can be restored to its original shape by the deflection restoring force of the resin after unloading. It is characterized by being attached,
Windproof snow fence.   The windproof and snowproof fence according to claim 1, wherein a windproof net is stretched between adjacent struts so that the entangled yarn is positioned in a direction in which the windproof net is stretched.   The connecting device not including a spring is provided with a plurality of support bolts projecting horizontally on the side surface of the support column, and a vertical shaft provided in parallel with the support column and slidably passed through and supported by the plurality of support bolts. A frame member, a grip column having a C-shaped cross section attached to a side surface of the vertical frame member, and a locking rod that can be inserted and locked in a receiving hole with a slit of the grip column, Both end portions of the windbreak net are sandwiched across the entire length between the outer peripheral surface of the locking rod around which the end is wound and the inner peripheral surface of the accommodation hole of the grip column in which the locking rod is inserted. The windproof snow fence according to claim 1, wherein   A part of the grip column is screwed with a plurality of fixing bolts capable of pressing the locking rod in the receiving hole toward the slit side, and the side end portion of the windproof net is connected to the grip column via the fixing bolt. The windproof and snowproof fence according to claim 3, wherein the windproof and snow fence is connected to each other inseparably.   5. The windproof and snowproof fence according to claim 3, wherein the grip column is slidably attached to a side surface of the vertical frame member along the vertical direction.   The windproof and snowproof fence according to claim 1, wherein the coating resin and the internal resin constituting the resin are acrylic emulsion resins.   The windproof / snowproof fence according to claim 1, wherein the woven / knitted sheet is any one of polyester fiber, polyethylene fiber, and aramid fiber.

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