JP7493733B2 - Animal protection net - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act. Published on the front page of the Nikkan Mokuzai Shimbun on January 17, 2020. Published at a seminar on animal protection materials in Shizuoka Prefecture (within the afforestation area managed by the Haruno Forestry Association (Haruno-cho, Tenryu-ku, Hamamatsu City, Shizuoka Prefecture)) on October 20, 2020 to October 21, 2020. Distributed to 538-11 Chiyo, Aoi-ku, Shizuoka City, Shizuoka Prefecture, Shizuoka City Forestry Association, and 130 others on December 15, 2019. Distributed to 7182-78 Kaigandori, Karatsu City, Saga Prefecture, Genkai Kogyo, and 18 others on March 23, 2020. Delivered to 538-11 Chiyo, Aoi-ku, Shizuoka City, Shizuoka Prefecture, Shizuoka City Forestry Association, and 23 others on December 16, 2019.

The present invention relates to an animal prevention net that is installed to prevent animals from invading fields where agricultural crops are grown, forested areas where seedlings are planted, etc.

In recent years, there has been an increase in damage caused by large wild animals such as boars and deer, and small wild animals such as rabbits and civets invading agricultural fields where crops are grown and reforested areas where seedlings have been planted, and eating the crops, damaging the bark of the seedlings, and eating the young leaves. Measures taken to combat such damage caused by pests include installing animal protection nets made of synthetic fibers, for example, around agricultural fields and reforested areas. Animal protection nets that use synthetic fiber twisted yarn with metal wires as the material for the fence-like main netting, and that have even greater strength, are also being adopted (see Patent Document 1, etc.).

The anti-animal net described in Patent Document 1 is made of synthetic fibers containing metal wires, with the metal wires being soft stainless steel wires (e.g., SUS304 W1 as specified in JIS G 4309) with a diameter of 0.2 mm, and the synthetic fiber twisted yarns being polyethylene twisted yarns with a connected fineness of 400 d (denier) and excellent weather resistance. The anti-animal net described in Patent Document 1, which is constructed in this way, is able to prevent animals from biting through the net to some extent by using the metal wires, but there are still cases where the yarns are bitten through by small animals such as rabbits. Here, the cutting strength can be increased by making the metal wires thicker, but the thicker the metal wires, the heavier they become, which creates the problem of impaired workability.

An animal-prevention net that uses high-strength fibers with high tensile strength has been proposed (see, for example, Patent Document 2). This animal-prevention net is made by twisting together first and second threads of different types at a specified twist number to form a net. Specifically, a high-strength fiber with a strength per unit area of 7 g/d or more (for example, Izanas (registered trademark) manufactured by Toyobo Co., Ltd.) is used as the first thread, and the animal-prevention net is made by twisting this with a second thread made of normal fiber at a twist number of 10 T/M to 200 T/M.

JP 2003-199479 A JP 2004-169236 A

However, even the anti-animal netting described in Patent Document 2 can be bitten through, and there have been reported cases in which the netting caused more damage than the anti-animal netting made of soft stainless steel wire.

The present invention has been made in consideration of the above circumstances, and aims to provide an animal prevention net that can effectively prevent damage to crops, seedlings, etc. caused by animals of different sizes and types, while minimizing the decrease in workability caused by increased weight.

The animal-proof net of the present invention, which solves the above-mentioned object, is a high-strength animal-proof net made by continuously forming meshes with a predetermined opening using a cord body made by twisting together a plurality of metal wires with a predetermined wire diameter and a plurality of synthetic fiber threads with a predetermined thickness,
The metal wire is characterized in that it is made of a hard stainless steel wire of SUS304 WPB or SUS304 WPA specified in JIS G 4314 having a wire diameter of 0.1 to 0.3 mm.

The animal-proof net of the present invention uses hard stainless steel wire of SUS304 WPB or SUS304 WPA as specified in JIS G 4314, with a wire diameter of 0.1 mm to 0.3 mm, as the metal wire. This results in a significantly improved cutting strength compared to conventional nets that use soft stainless steel wire as the metal wire or nets that use high-strength polyethylene fiber instead of metal wire. This effectively prevents large, powerful animals from invading farm fields or plantations, as well as small animals with strong biting power from invading farm fields or plantations. In addition, the weight can be reduced to the same level as nets that use soft stainless steel wire, and a decrease in workability can be prevented.

In the animal prevention net of the present invention, the high-strength net may be at least partially made of a wire rope-like wire rope body composed of one hard stainless steel wire arranged in the center and multiple hard stainless steel wires twisted around the hard stainless steel wire.

By using this type of animal protection netting, the tensile strength is further improved, further increasing the deterrent effect, especially against large, powerful animals.

The animal prevention net can also be constructed by combining multiple types of high-strength mesh bodies, in which the wire diameter, number of wires, or twisting method of the hard stainless steel wires are different according to the size and characteristics of the animals to be prevented from entering, with simple mesh bodies that do not have metal wires.

Furthermore, in the animal prevention net of the present invention, it is also a preferred embodiment that the net has an auxiliary net for threading ropes, which is made using soft stainless steel wire of SUS304 W1 as specified in JIS G 4309 or high-strength polyethylene fiber yarn instead of the hard stainless steel wire.

By using this type of anti-animal netting, the section through which the rope passes becomes a soft auxiliary netting body that can flexibly deform, preventing kinks in the rope when the anti-animal netting is deployed, allowing for smooth deployment of the anti-animal netting.

The animal prevention net of the present invention can provide an animal prevention net that can effectively prevent damage to crops, seedlings, etc. caused by animals of different sizes and types while minimizing the decrease in workability due to increased weight.

1 is a perspective view showing an animal prevention net according to a first embodiment of the present invention; FIG. 2 is a front view of the animal prevention net shown in FIG. 1 . FIG. 3 is an enlarged view of a portion of the mesh of the animal prevention net shown in FIG. 2 . 2 is a side view showing the twisted structure of two types of cords in the high-strength mesh portion of the animal-proof net shown in FIG. 1. FIG. 1A is a side view showing another twisted structure of the cords in the high-strength mesh portion of the animal-proof net shown in FIG. 1, and FIG. 11 is a perspective view showing an animal prevention net according to a second embodiment of the present invention. FIG. A diagram showing an animal prevention net according to a third embodiment of the present invention. A front view showing an animal prevention net according to the fourth embodiment of the present invention. 9 is a side view showing the twisted structure of two types of cords in the auxiliary mesh portion of the animal-proof net shown in FIG. 8 . FIG. 2 is an explanatory diagram showing the procedure for installing the animal prevention net of the present invention. FIG. 1A is a front view showing a test device used in a tensile breaking strength test conducted to examine the effects of the present invention, and FIG. 1B is an enlarged view of the periphery of a test site. 1 is a graph showing the results of a tensile breaking strength test carried out to examine the effects of the present invention. 1 is a graph showing the results of a push-off test conducted to test the effects of the present invention.

The following describes in detail the embodiment of the present invention with reference to the drawings.

First, we will use the first embodiment shown in Figures 1 to 5 as an example to specifically explain the overall structure of the animal protection net of the present invention and the twisted structure of the strings, which is its main part.

Figure 1 is a perspective view showing an animal protection net 1 according to a first embodiment of the present invention, and Figure 2 is a front view of the animal protection net 1 shown in Figure 1. Note that Figure 2 shows the skirt portion 19 stretched relative to the fence portion 21. Figure 3 is an enlarged view of a portion of the mesh of the animal protection net 1 shown in Figure 2.

An animal-proof net is a net for keeping out pests that is installed around farm fields or reforested areas to prevent animals from entering the fields or reforested areas. In some cases, it is made using a string body made of multiple twisted synthetic fiber threads 3 such as polyethylene, but the basic element of the animal-proof net 1 of the present invention is a high-strength net body 17 made by continuously forming meshes 15 with specified openings using a string body 5 made of multiple metal wires with a specified wire diameter D and multiple synthetic fiber threads 3 with a specified thickness.

As a characteristic feature of the present invention, the metal wire is made of SUS304 WPB hard stainless steel wire (hereinafter sometimes referred to as WPB hard stainless steel wire) 7, 9 specified in JIS G 4314 with a wire diameter D of 0.1 to 0.3 mm. Note that existing animal prevention nets use SUS304 W1 soft stainless steel wire (hereinafter sometimes referred to as W1 soft stainless steel wire) specified in JIS G 4309 as the metal wire. This W1 soft stainless steel wire is a soft stainless steel wire that has been annealed and is easy to process, and the tensile strength of a single wire with a wire diameter D of 0.19 mm is approximately 20.35 (N).

In contrast, the WPB hard stainless steel wires 7 and 9 used in the present invention are metal wires that are hard and have high tensile strength and are used for springs, etc. For a wire diameter D of 0.19 mm, the tensile strength of the single wire is approximately 61.27 (N), which is approximately three times the tensile strength of the W1 soft stainless steel wire.

In this embodiment, the animal protection net 1 is composed of a skirt portion 19 covering the ground surface GL and a fence portion 21 rising from the ground surface GL, and two types of mesh bodies 17, 29 made of different materials are used for the lower portion 23 and upper portion 27 of the fence portion 21. Specifically, a simple mesh body 29 made of a twisted string of 30 polyethylene threads 3 with a standard thickness of 400d (denier) (440T (decitex)) is arranged as the skirt portion 19. Also, a high-strength mesh body 17 made of a string body 5 twisted with the polyethylene threads 3, each of which has a wire diameter D of 0.19 mm, is arranged as the lower portion 23 of the fence portion 21. Here, it is preferable to use an auxiliary mesh body 31 (see FIG. 8) which is more flexible than the high-strength mesh body 17, which will be described in detail later, for the connection portion (portion through which the rope 35 passes) between the fence portion 21 and the skirt portion 19.

Furthermore, the upper part 27 of the fence section 21 is configured with a simplified mesh body 29, which is made of, as an example, 30 twisted polyethylene threads 3 having a standard thickness of 400d (440T), just like the skirt section 19, to form the animal prevention net 1A.

In this embodiment, as an example, an animal prevention net 1A is adopted in which the length in the deployment direction Y of the animal prevention net 1A is 50 m, the mesh 15 is diamond-shaped with a side length of 5 cm, the skirt portion 19 has a width direction X dimension of 30 cm, the lower portion 23 of the fence portion 21 has a height direction Z dimension of 1 m20 cm, and the upper portion 27 of the fence portion 21 has a height direction Z dimension of 60 cm. The reason for arranging the net bodies 17 and 29 in this manner is that the high-strength net body 17 is arranged in a range of 1 m20 cm in the height direction Z from the ground surface GL at the lower portion 23 of the fence portion 21, where animals are most likely to hit or bite, to provide effective animal prevention measures, and the simplified net body 29 made of only soft and lightweight polyethylene threads 3 is arranged in the remaining skirt portion 19 and upper portion 27 of the fence portion 21 to reduce the weight and cost of the entire animal prevention net 1A. The skirt portion 19 is also provided as a measure against animals digging holes from the ground surface GL and passing through the ground below the fence portion 21 to enter the field, etc.

In addition, the animal protection net 1A of this embodiment is provided with three ropes 35 extending in the deployment direction Y at three locations: the upper edge of the fence portion 21, the connection between the fence portion 21 and the skirt portion 19, and the lower edge of the skirt portion 19. The ropes 35 may be, for example, polyethylene ropes with a diameter of 5 to 10 mm.

Figure 4 is a side view showing the twisted structure of two types of strings in the high-strength mesh portion of the animal-proof net 1 shown in Figure 1. Also, Figure 5(a) is a side view showing another twisted structure of the strings in the high-strength mesh portion of the animal-proof net 1 shown in Figure 1, and Figure 5(b) is a cross-sectional view of the metal wire portion.

As the high-strength mesh body 17, in addition to the high-strength mesh body 17A shown in FIG. 4(a) and having the above-mentioned configuration, a high-strength mesh body 17B using a cord body 10 having a configuration shown in FIG. 4(b) in which the number of WPB hard stainless steel wires 9 and the wire diameter D are different may be used. Also, as shown in FIG. 5, it is possible to adopt a high-strength mesh body 17C using a wire rope body 8' using WPB hard stainless steel wires 7 having a different twisting structure.

The high-strength mesh 17B shown in FIG. 4(b) is a high-strength mesh that uses a cord 10 made by twisting together four WPB hard stainless steel wires 9 with a wire diameter D of 0.29 mm, which is thicker than the high-strength mesh 17A shown in FIG. 4(a), with a polyethylene thread 3, and is a high-strength mesh with high cutting strength that is suitable for animals with strong biting power, such as rabbits.

On the other hand, the high-strength mesh body 17C shown in FIG. 5 is a high-strength mesh body using a wire rope body 8' having a wire rope-like twisted structure in which seven WPB hard stainless steel wires 7 with a wire diameter D of 0.19 mm are used, one of which is the core wire 37 located at the center, and the remaining six are twisted around the core wire 37 to form twisted wires 39. The tensile strength of this high-strength mesh body 17C is further increased by the wire rope-like twisted structure, making it a high-strength mesh body suitable for strong animals such as wild boars.

Next, other embodiments of the animal prevention net 1 of the first embodiment shown in Figures 1 to 5 will be described. In the other embodiments described below, differences from the first embodiment shown in Figures 1 to 5 will be mainly described, and components with the same names as those in the first embodiment shown in Figures 1 to 5 will be described using the same reference numerals used so far, and duplicate descriptions may be omitted.

Figure 6 is a perspective view showing an animal protection net according to the second embodiment of the present invention.

As shown in Figure 6, the animal protection net 1B according to the second embodiment of the present invention is an animal protection net with the skirt portion 19 removed from the structure of the animal protection net 1A according to the first embodiment described above. Note that the material and dimensions of the upper portion 27 and lower portion 23 of the fence portion 21, the size of the mesh 15, and the twisted structure of the string body 5 are the same as those of the animal protection net 1A according to the first embodiment.

In addition, in this embodiment, since there is no skirt portion 19, the number of ropes 35 is two, one less than that of the animal prevention net 1A of the first embodiment. The two ropes 35 are arranged in two locations, one above the other, near the top edge of the upper portion 27 of the fence portion 21, and one near the bottom edge of the lower portion 23 of the fence portion 21. In this embodiment as well, it is preferable to use an auxiliary mesh body 31 (see Figure 8), which is more flexible than the high-strength mesh body 17, as described in detail below, for the portion of the lower portion 23 of the fence portion 21 through which the rope 35 passes.

The animal prevention net 1B configured in this way is lighter and easier to carry by omitting the skirt portion 19 and one rope 35, and the burden on the worker when setting it up is reduced. In addition, since it has an excellent animal prevention effect against animals that are not likely to dig into the ground and invade the field, it is desirable to select and use either the first embodiment or the second embodiment as appropriate depending on the type of animal to be prevented from invading.

Figure 7 is a perspective view showing an animal protection net according to the third embodiment of the present invention.

As shown in Fig. 7, the animal prevention net 1C according to the third embodiment of the present invention further subdivides the structure of the animal prevention net 1A according to the first embodiment described above, dividing the fence section 21 into three parts: a lower section 23, a middle section 25, and an upper section 27. The fence section 21 is divided into three sections, and a skirt section 19 is added to the skirt section 19 to create four sections, each of which has a mesh body 17, 29 with a different structure. In other words, this animal prevention net 1C is an animal prevention net that is constructed by combining multiple types of high-strength mesh bodies 17A, 17B, 17C in which the wire diameter D, number of wires, or twisting method of the WPB hard stainless steel wires 7, 9 are different according to the characteristics of the animals to be prevented from entering, and a simple mesh body 29 that does not have metal wires.

Specifically, a high-strength mesh body 17C using a wire rope body 8' in the form of a wire rope as shown in Figure 5 is disposed in the skirt portion 19 covering the ground surface GL. Also, in the lower portion 23 of the fence portion 21 rising from the ground surface GL (for example, within a range of 60 cm in the height direction Z from the ground surface GL), a high-strength mesh body 17B using WPB hard stainless steel wire 9 with a thicker wire diameter D and a reduced number of wires as shown in Figure 4 (b) is disposed. Even in this embodiment, it is preferable to use an auxiliary mesh body 31 (see Figure 8), which is more flexible than the high-strength mesh body 17, as described in detail later, in the connection portion (portion through which the rope 35 passes) between the lower portion 23 of the fence portion 21 and the skirt portion 19.

Furthermore, in the middle section 25 of the fence section 21 rising from the ground surface GL (for example, in the range from 60 cm to 120 cm above the ground surface GL), a high-strength mesh body 17A is arranged using WPB hard stainless steel wires 7 with a thinner wire diameter D and an increased number of wires, as shown in Figure 4(a). Furthermore, in the upper section 27 of the fence section 21 rising from the ground surface GL (for example, in the range from 120 cm to 180 cm to 200 cm above the ground surface GL), a simple mesh body 29 without metal wires is arranged.

When an animal prevention net 1C having such a configuration is adopted, the skirt portion 19 can deal with strong animals such as wild boars that try to dig holes from the ground surface GL and invade the field. The lower portion 23 of the fence portion 21 can effectively prevent animals with strong biting power such as rabbits from invading the field. Furthermore, the middle portion 25 of the fence portion 21 can prevent animals with a certain degree of strength and biting power such as deer from invading the reforestation area. Furthermore, the upper portion 27 of the fence portion 21 can prevent animals with high jumping power from jumping over the fence and invading the field.

Figure 8 is a diagram showing an animal protection net according to a fourth embodiment of the present invention. Also, Figure 9 is a side view showing the twisted structure of two types of string bodies in the auxiliary mesh body part of the animal protection net shown in Figure 8.

As shown in FIG. 8, the animal protection net 1D according to the fourth embodiment of the present invention is an embodiment in which an auxiliary mesh body 31, which is more flexible than the high-strength mesh body 17, is used instead of a part of the high-strength mesh body 17 constituting the basic element. Specifically, the portion through which the rope 35 passes, which is provided on the upper and lower sides of the high-strength mesh body 17, is replaced with an auxiliary mesh body 31 using a string body 12 using a W1 soft stainless steel wire 11 as shown in FIG. 9(a). By applying the auxiliary mesh body 31 to the mesh 15 in the portion through which the rope 35 passes, it becomes possible to prevent a problem in advance in which the high-strength mesh body 17 cannot be pulled out due to a kink (bump) in the rope 35 that occurs in the high-strength mesh body 17 when the animal protection net 1D is installed.

The section through which the rope 35 passes may be an auxiliary mesh 33 using a string 14 made of high-strength polyethylene fiber thread 13 as shown in FIG. 9(b). Here, "IZANAS (registered trademark)" manufactured by Toyobo Co., Ltd. may be used as an example of the high-strength polyethylene fiber thread 13.

Next, the procedure for installing the animal protection net will be explained using the animal protection net 1A according to the first embodiment described above as an example.

Figure 10 is an explanatory diagram showing the installation procedure for the animal protection net of the present invention.

First, the posts 41 are erected at appropriate intervals at the installation site where the animal prevention net 1A will be installed. The packaged animal prevention net 1D shown in FIG. 10(a) is brought to the installation site where the posts 41 have been erected, and the binding strings 43 are untied and the net is opened as shown in FIG. 10(b). The packaged animal prevention net 1D includes three ropes 35 for supporting the animal prevention net 1A, as shown in FIG. 10(b).

Next, as shown in FIG. 10(c), the three ropes 35 are threaded alternately through the meshes 15 at three locations on the upper edge of the fence portion 21 and the upper and lower edges of the skirt portion 19, and the ends of the three ropes 35 are extended in the deployment direction Y, as shown in FIG. 10(d).

Next, the animal prevention net 1D is gradually pulled out in the unfolding direction Y, and each pulled out animal prevention net 1D is hooked to the support pole 41 in order and installed. Then, by pulling out all the animal prevention nets 1D and hooking them to the support poles 41, the installation of the animal prevention net 1D is completed as shown in FIG. 10(e).

In this embodiment, the rope 35 is passed through the upper edge of the fence portion 21, which is made of a simple mesh body 29, and the lower edge of the skirt portion 19, which is also made of a simple mesh body 29. Furthermore, if the auxiliary mesh body 31 shown in FIG. 8 (see FIG. 8) is used for the connection portion between the fence portion 21 and the skirt portion 19 (portion through which the rope 35 is passed), the occurrence of kinks (bumps) in the rope 35 can be suppressed, and the animal prevention net 1A can be smoothly deployed and installed. In this way, when the rope 35 is passed through the portion made of the high-strength mesh body 17, the auxiliary mesh body 31, which has greater flexibility than the high-strength mesh body 17, can be used for the portion through which the rope 35 is passed.

Next, based on Figures 11 and 12, we will explain the details of the tensile breaking strength test conducted to test the effectiveness of the present invention and the test results.

Figure 11 (a) is a front view of the test equipment used in the tensile breaking strength test conducted to test the effectiveness of the present invention, and (b) is an enlarged view of the test area. Figure 12 is a graph showing the test results of the tensile breaking strength test conducted to test the effectiveness of the present invention.

The tensile breaking strength test was carried out at the Shizuoka Prefectural Industrial Technology Research Institute Hamamatsu Industrial Technology Support Center, and a Shimadzu Autograph AG-250NXPlus manufactured by Shimadzu Corporation was used as the test device 45. Four types of mesh bodies with meshes 15 measuring 5 cm on a side were prepared as test specimens. The mesh bodies used were 30 strands of 400d (440T) polyethylene yarn 3 twisted together with the following high-strength polyethylene fiber yarn, soft stainless steel wire, and two types of hard stainless steel wire with different wire diameters D twisted together.

The high-strength polyethylene fiber thread used was the aforementioned "IZANAS" of 1200d, and a mesh made by twisting three of these together was designated "Conventional Product 1". The soft stainless steel wire used was a W1 soft stainless steel wire with a wire diameter D of 0.19 mm, and a mesh made by twisting eight of these together was designated "Conventional Product 2". In addition, two types of WPB hard stainless steel wire were prepared as the hard stainless steel wire: a thin one with a wire diameter D of 0.19 mm and a thick one with a wire diameter D of 0.29 mm. Of these, eight of the thin WPB hard stainless steel wires with a wire diameter D of 0.19 mm were used, and a mesh made by twisting these together was designated "Product of the present invention 1". In addition, a mesh made by twisting four of the thick WPB hard stainless steel wires with a wire diameter D of 0.29 mm was designated "Product of the present invention 2".

The test method was as follows: the mesh 15 of the four types of mesh bodies described above was supported vertically on the test device 45 for two squares as shown in Fig. 11(a), and as shown in Fig. 11(b), the mesh 15 for two squares was supported on the upper support part 49 with a replaceable blade type plane blade 47 attached to the inside of the upper part as shown in Fig. 11(b). Meanwhile, the lower part of the mesh 15 for two squares was fixed to the lower support part 51, and the tensile breaking strength (N) was measured when it was cut by separating the upper support part 49 and the lower support part 51 at a test speed of 20 mm/min.

The test results of the tensile breaking strength test are shown in Figure 12, and the tensile breaking strength of "conventional product 1" was approximately 100 (N), the tensile breaking strength of "conventional product 2" was approximately 270 (N), the tensile breaking strength of "product of the present invention 1" was approximately 500 (N), and the tensile breaking strength of "product of the present invention 2" was approximately 600 (N).

These results show that although "Conventional Product 1" exhibits high performance in terms of simple tensile strength, its tensile breaking strength in the tensile breaking test conducted this time was low, making it vulnerable to being bitten off by animals. Furthermore, "Conventional Product 2" has a higher tensile breaking strength than Conventional Product 1, showing a value more than twice as high, confirming that it does have a fairly high tensile breaking strength.

In contrast, "Product 1 of the present invention" and "Product 2 of the present invention" showed a tensile breaking strength that was nearly or more than twice that of "Conventional Product 2," demonstrating extremely high performance.

The animal protection net 1 of the present invention, which has as its basic element the high-strength net 17 that exhibits such high performance, is therefore able to effectively prevent damage to crops, seedlings, etc. caused by animals of different sizes and types, while minimizing the decrease in workability that would otherwise result from increased weight, and by further improving cutting strength.

The animal protection net 1 of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the claims. For example, the wire diameter D and number of the WPB hard stainless steel wires 7, 9 are not limited to those described in the above-mentioned embodiment. They can be adjusted as appropriate within the range that does not increase the weight to the extent that it impairs workability. Similarly, the thickness, number and material of the synthetic fiber threads 3 twisted with the WPB hard stainless steel wires 7, 9 are not limited to those described in the above-mentioned embodiment, and can be adjusted as appropriate. Furthermore, the structure for twisting the WPB hard stainless steel wires 7, 9 and the synthetic fiber threads 3 is not limited to the structure described in the above-mentioned embodiment, and various twisting structures used in synthetic resin ropes, etc. can be adopted.

The mesh 15 is not limited to a square or diamond shape with sides of 5 cm, but may be a square or diamond shape with sides of different sizes, such as 7 cm or 3 cm. The shape of the mesh 15 is also not limited, and various shapes can be used, such as a rectangle, trapezoid, or polygonal shape such as a triangle or hexagon. It is also possible to make an animal protection net 1 by combining meshes 15 of different sizes in the skirt portion 19, the lower portion 23, the middle portion 25, and the upper portion 27 of the fence portion 21.

Furthermore, in the above-mentioned embodiment, the WPB hard stainless steel wire is used as the hard stainless steel wire, but instead of the WPB hard stainless steel wire, a hard stainless steel wire of SUS304 WPA specified in JIS G 4314 (hereinafter sometimes referred to as WPA hard stainless steel wire) can be used. Although the WPA hard stainless steel wire is slightly inferior to the WPB hard stainless steel wire in terms of tensile strength, the use of this WPA hard stainless steel wire still sufficiently improves the cutting strength compared to those using soft stainless steel wire or high-strength polyethylene fiber. Therefore, it is possible to effectively prevent the intrusion of large animals with strong strength into farm fields and reforestation areas, and the intrusion of small animals with strong biting power into farm fields and reforestation areas. In addition, the weight can be reduced to the same level as that of the soft stainless steel wire, and the decrease in workability can also be prevented.

Note that even if a component is included only in the description of each of the embodiments and variations described above, that component may be applied to other embodiments or other variations.

Next, we will explain the details of the additional push-through test that was conducted, assuming a case in which an animal uses its teeth to bite through the wire part of the net, and the results of that test.

The push-off test, like the tensile breaking strength test, was carried out at the Shizuoka Prefectural Industrial Technology Research Institute's Hamamatsu Industrial Technology Support Center, and a Shimadzu Autograph AG-250NXPlus manufactured by Shimadzu Corporation was used as the test equipment. Six types of mesh bodies with mesh 15 measuring 5 cm on a side were prepared as test specimens. The mesh bodies used were a twisted combination of 30 400d (440T) polyethylene threads 3 (comparative example), and a twisted combination of the following high-strength polyethylene fiber threads, soft stainless steel wire, and three types of hard stainless steel wires with different wire diameters D.

The high-strength polyethylene fiber yarn used was the aforementioned 1200d "IZANAS", and a mesh made by twisting three of these together was designated "Conventional Product 3". The soft stainless steel wire used was a W1 soft stainless steel wire with a wire diameter D of 0.19 mm, and a mesh made by twisting eight of these together was designated "Conventional Product 4". Two types of WPB hard stainless steel wire were prepared as the hard stainless steel wire: one with a thin wire diameter D of 0.19 mm and one with a thick wire diameter D of 0.29 mm. Of these, eight of the thin WPB hard stainless steel wires with a wire diameter D of 0.19 mm were used, and the mesh made by twisting these together was designated "Product 3 of the present invention". Furthermore, a mesh body made by twisting together four large-diameter WPB hard stainless steel wires with a wire diameter D of 0.29 mm was used and designated "Product of the present invention 4," and a mesh body made by twisting together eight large-diameter WPB hard stainless steel wires with a wire diameter D of 0.29 mm was used and designated "Product of the present invention 4."

The test method used was to use test device 45, in which the six types of mesh mentioned above were clamped vertically with hard pliers, and a push-through test was carried out to apply force from above to push through the mesh, measuring the push-through strength (N).

The test results of the push-through test are shown in Figure 13. The push-through strength of "Conventional Product 3" was approximately 220 (N), the same as the "Comparative Example", and the push-through strength of "Conventional Product 4" was approximately 390 (N), which was approximately 170 (N) stronger than the "Comparative Example". On the other hand, the push-through strength of "Product 3 of the Invention" and "Product 4 of the Invention" was approximately 520 (N), which was approximately 300 (N) stronger than the "Comparative Example". The push-through strength of "Product 5 of the Invention" was approximately 700 (N), which was approximately 480 (N) stronger than the "Comparative Example".

These results show that when an animal uses its teeth to bite through the wire portion of the net, "Conventional Product 3" has roughly the same effect as the "Comparative Example." "Inventive Product 3" has the same weight as "Conventional Product 4," but has just under twice the pushing strength. "Inventive Product 4" is slightly lighter than "Conventional Product 4," but has just under twice the pushing strength. "Inventive Product 5" has about 2.5 times the pushing strength of "Conventional Product 4."

In addition, the results of the tensile breaking strength test (see FIG. 12) and the push-cut test (see FIG. 13) were examined based on the height of the animal and the shape of the teeth. As a result, a high-strength mesh body 17B using the WPB hard stainless steel wire 9 with a thicker wire diameter D shown in FIG. 4(b) is placed in the lower part 23 (for example, in the range of 50 cm from the ground surface GL in the height direction Z) of the fence part 21 rising from the ground surface GL shown in FIG. 7. Furthermore, a high-strength mesh body 17A using the WPB hard stainless steel wire 7 with a thinner wire diameter D shown in FIG. 4(a) is placed in the middle part 25 (for example, in the range of 50 cm to 150 cm from the ground surface GL) of the fence part 21 rising from the ground surface GL. Furthermore, a simple mesh body 29 without metal wires is preferably placed in the upper part 27 (for example, in the range of 150 cm to 180 cm to 200 cm from the ground surface GL) of the fence part 21 rising from the ground surface GL.

By adopting this type of animal prevention net, it is possible to effectively prevent the intrusion of rabbits and other animals with strong biting power by the high-strength mesh body 17B, which is placed in the lower part 23 of the fence part 21 and uses WPB hard stainless steel wire 9 with a large wire diameter D and high cutting strength and pushing strength. Furthermore, it is possible to effectively prevent the intrusion of deer and other animals with relatively strong biting power and cutting power by the high-strength mesh body 17A, which is placed in the middle part 25 of the fence part 21 and uses WPB hard stainless steel wire 7 with a small wire diameter D. Furthermore, it is possible to prevent the intrusion of animals that try to jump over the fence part and enter the field by the simple mesh body 29 placed in the upper part 27 of the fence part 21 at low cost and with a reduced weight.

Furthermore, taking into account the characteristics of the material, in order to make it lighter and to improve the efficiency of the manufacturing method, the mesh may be made by mixing WPB hard stainless steel wire with W1 soft stainless steel wire, W2 stainless steel wire, high-strength polyethylene fiber thread, etc.

The following is a summary of how the invention was perfected.

Fishing nets, golf course nets, and other nets were traditionally made from polyethylene, which is cheap and does not deteriorate easily. For the past 25 years, it has also been used in forestry to keep animals away, but because it was made from recycled nets from the fishing industry, they contained salt, which animals love, and were completely ineffective.

There has been discussion about strengthening the soft polyethylene netting, and in the past a proposal was made to mix soft stainless steel wire into the netting, but in an era when the numbers of protected species such as Japanese serow and Japanese deer were small and the damage caused by rabbits was minimal, soft polyethylene netting was effective enough.

Over the past decade, animal prevention netting that mixes in "IZANAS (high-strength polyethylene fiber thread)" instead of stainless steel wire has become popular due to its strong tensile strength. At manufacturing sites, "IZANAS" is preferred over soft stainless steel wire because it puts less strain on knitting machines and can be woven more efficiently. However, at sites where animal prevention netting is used, with the increase in the number of animals, "IZANAS" and soft stainless steel wire have become more prone to tearing, and the effectiveness of the animal prevention netting has declined significantly.

Taking these points into consideration, we conducted thorough research. The original problem with nets was that the mesh (intersections) could shift, allowing fish to escape or golf balls to fall through. For this reason, "tensile tests of materials" were commonly conducted. However, in "tensile tests of materials," the strength is determined by the amount of polyethylene that makes up the entire net, which does not match the strength required for animal control. Despite this, the tensile values were respected in forestry work. As a result, although "IZANAS" showed high tensile strength, this did not translate into animal control effects. For this reason, a shift from polyethylene nets to iron fences is underway.

Since animals use their teeth to break things, we chose materials with the idea that "if the material is reinforced with a material harder than the hardness of the teeth, it will be less likely to break." Teeth are made of enamel, so the Vickers hardness of teeth varies from one to another, but is generally around 270HV to 366HV. Soft stainless steel wires in circulation generally have a converted value of around 210HV. Since "IZANAS" is a fiber, there is no Vickers value, but in the local area where animal prevention nets are used, soft stainless steel wires were more effective than "IZANAS," so this was not considered. Next, hard stainless steel wires are around 590HV, while titanium alloy wires are estimated to be around 540HV when made into wire, which is slightly softer than hard stainless steel wire and costs several tens of times more, so we did not adopt it. From these results, we assumed that animals would try to cut the net even if it meant damaging their teeth (enamel) if the net was soft, but would not try to do so if the net was hard. From among the various types of stainless steel wire, we selected hard stainless steel wires such as SUS304 WPB or SUS304 WPA, and completed the present invention after extensive research.
In addition, the animal prevention net described above has a skirt portion covering the ground surface, and the high-strength net body using the wire rope body is arranged on the skirt portion,
The high-strength mesh body using the hard stainless steel wire with a thicker wire diameter and a reduced number of wires is disposed at the lower part of the fence portion rising from the ground surface,
The high-strength mesh body using the hard stainless steel wire having a reduced wire diameter and an increased number of wires is disposed in the middle of the fence portion,
A simple mesh body not including the metal wire may be disposed on the upper portion of the fence portion.
By adopting such an animal prevention net, it is possible to effectively prevent the intrusion of wild boars, which try to dig the ground surface and invade the field with strong force, by the high-strength steel body using the wire rope body with strong tensile strength, which is arranged in the skirt part. In addition, it is possible to effectively prevent the intrusion of rabbits, which have strong biting power, by the high-strength net body using the hard stainless steel wire with a thick wire diameter and strong cutting strength, which is arranged in the lower part of the fence part. Furthermore, it is possible to effectively prevent the intrusion of deer, which have a relatively strong force and biting power, by the high-strength net body using the hard stainless steel wire with a thin wire diameter and an increased number of wires, which is arranged in the middle part of the fence part. Furthermore, it is possible to prevent the intrusion of animals which try to jump over the fence part and invade the field, by the simple net body arranged in the upper part of the fence part, while reducing the weight and reducing the cost.

1. Animal protection net 3. Polyethylene yarn (synthetic fiber yarn)
5 Cord body 7 (metal wire and synthetic fiber thread twisted together) (thin diameter) WPB hard stainless steel wire 8 Cord body 8' (thin diameter WPB hard stainless steel wire twisted together) Wire rope body 9 (large diameter) WPB hard stainless steel wire 10 Cord body 11 (thick diameter WPB hard stainless steel wire twisted together) W1 soft stainless steel wire (metal wire)
Reference Signs List 12 Cord body (twisted together W1 soft stainless steel wires) 13 High-strength polyethylene fiber thread 14 Cord body (twisted together high-strength polyethylene fiber threads) 15 Mesh 17 High-strength mesh body 19 Skirt portion 21 Fence portion 29 Simplified mesh body 31, 33 Auxiliary mesh body 35 Rope 45 Test device D Wire diameter

Claims (3)

An animal-proof net having a high-strength net body made by continuously forming meshes with a predetermined number of openings using a string body made by twisting together a plurality of metal wires having a predetermined wire diameter and a plurality of synthetic fiber threads having a predetermined thickness,
The animal-proof net is characterized in that the metal wire is made of hard stainless steel wire of SUS304 WPB or SUS304 WPA specified in JIS G 4314 and having a wire diameter of 0.1 to 0.3 mm. An animal-proof net according to claim 1, characterized in that at least a portion of the high-strength net is made of a wire rope-like wire body composed of one hard stainless steel wire placed in the center and multiple hard stainless steel wires twisted around the hard stainless steel wire. 3. The animal-proof net according to claim 1 or 2, characterized in that it has an auxiliary net for threading ropes, which is made using soft stainless steel wire of SUS304 W1 specified in JIS G 4309 or high-strength polyethylene fiber yarn instead of the hard stainless steel wire.

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