Reflective plate for fruit trees

Abstract

To provide a reflective plate for fruit trees that enables appropriate diffusion reflection of reflected light and allows simplified installation and maintenance.SOLUTION: A reflective plate 1 for fruit trees comprises a reflective portion 3 provided on one surface side of a disk-shaped reflective plate body 2 made of foamed resin. The reflective portion 3 has a white convexly curved surface 30, the central part of which protrudes the most. The outer diameter φ of the reflective portion 3 is 800-1400 mm, and the weight of the reflective plate body is 300-800 g.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reflector for fruit trees made of foamed resin that reflects light irradiated onto the ground around the fruit trees. [Background technology]

[0002] Conventionally, in the cultivation of fruit trees such as apples, peaches, and grapes, a cultivation method has been implemented in which agricultural reflective sheets are laid in the ridges of orchards and around the base of the fruit trees. In this cultivation method, the reflective sheets are used to reflect light irradiated onto the surrounding ground, allowing more light to be irradiated onto the leaves and fruit of the fruit trees, thereby aiding photosynthesis in the fruit trees and, for example, increasing the sugar content of the fruit and improving the color of the fruit.

[0003] Furthermore, as an agricultural reflective sheet such as the above, a laminated sheet composed of a cloth-like fiber aggregate layer, a specularly reflective foil-like metal layer such as aluminum foil, and a synthetic resin film layer is known (see, for example, Patent Document 1). This reflective sheet has a specularly reflective light-reflecting layer such as aluminum, so it can reflect light with high efficiency, and because it has low light transmittance, it also has the effect of suppressing the growth of weeds on the ground where it is laid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 3078702 Summary of the Invention [Problem to be solved by the invention]

[0005] However, reflective sheets with specular reflectivity as described above tend to reflect incident light only in a specific direction, and the reflected light may be locally irradiated, causing, for example, burnt fruit. In particular, because reflective sheets are thin members, they are easily affected by the topography of the place where they are laid, and if there is a depression or slope in the ground, the outer surface of the reflective sheet laid on top of it will be depressed, forming a partially concave reflective surface, which may cause the reflected light to be concentrated in one area.

[0006] Furthermore, the specular reflective sheeting described above is generally large, so it requires multiple people to lay it down, and since it easily flips over when the wind blows, it needs to be secured with pegs, making the laying work time-consuming. Furthermore, if fallen leaves or the like accumulate in the recesses of the specular reflective sheeting, the reflective efficiency decreases, so it needs to be cleaned regularly, which also requires time for maintenance.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a reflector for fruit trees that can diffuse and reflect reflected light appropriately and is easy to install and maintain. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention is characterized in that it comprises a reflecting portion made of foamed resin and provided on one side of a disk-shaped reflecting plate body, the reflecting portion having a white convex curved surface that protrudes most in the center, the outer diameter φ of the reflecting portion being 800 to 1400 mm, and the weight of the reflecting plate body being 300 to 800 g.

[0009] In the above-mentioned reflector for fruit trees, it is preferable that the radius of curvature R of the convex curved surface is 1000 to 1500 mm.

[0010] In the above-mentioned fruit tree reflector, it is preferable that unevenness resulting from foam beads constituting the foam resin of the reflector body is exposed on the surface of the reflecting portion.

[0011] In the above-mentioned fruit tree reflector, it is preferable that the other surface of the reflector body opposite to the surface on which the reflecting portion is provided has a stepped recessed portion that is deepest in the center.

[0012] In the above-mentioned reflector for fruit trees, it is preferable that the stepped corners of the recessed portion are chamfered to be rounded. [Effects of the Invention]

[0013] According to the fruit tree reflector of the present invention, the curved surface of the reflective portion is white, based on the color of the foam resin (foam beads) that constitutes the reflector body, which is the main component, and can appropriately diffuse and reflect reflected light. Furthermore, because the reflector body is a disk-shaped structure, it is not affected by the topography of the installation location, and the shape of the surface of the reflective portion does not change. Furthermore, by setting the outer diameter φ of the reflective portion to 800 to 1400 mm and the weight of the reflector body to 300 to 800 g, the reflector has an appropriate weight and wind flows along the convex curved surface, making it less likely to be blown away by the wind. Furthermore, since it does not require peg fastening, installation and maintenance can be easily performed. [Brief explanation of the drawings]

[0014] [Figure 1] 1A is a perspective view mainly showing the top surface of a reflector for fruit trees according to one embodiment of the present invention, and FIG. 1B is a perspective view mainly showing the bottom surface. [Figure 2] (a) is a plan view of the fruit tree reflector, (b) is a bottom view, (c) is a side view, and (d) is a cross-sectional side view. [Figure 3] 10A and 10B are diagrams showing examples of use of the fruit tree reflector. [Figure 4] 2 is a diagram showing the reflection characteristics of the fruit tree reflector and other reflective materials. FIG. [Figure 5] (a) is a diagram showing the wind tunnel test of the above-mentioned fruit tree reflector, and (b) is a diagram showing the wind tunnel test of a foam resin board. [Figure 6] 10(a) to 10(d) are side views showing variations of a reflector for fruit trees according to a modified example of the embodiment, which have different outer diameters φ and different curvature radii R of the convex curved surfaces. DETAILED DESCRIPTION OF THE INVENTION

[0015] A fruit tree reflector according to one embodiment of the present invention will be described with reference to Figures 1 and 2. As shown in Figures 1(a) and 1(b) and 2(a) to 2(d), the fruit tree reflector 1 of this embodiment comprises a foamed resin reflector body 2 and a reflecting portion 3 provided on one side of the reflector body 2. The reflecting portion 3 has a white convex curved surface 30. The other side of the reflector body 2 opposite the side on which the reflecting portion 3 is provided comprises a stepped recessed portion 4 that is deepest in the center.

[0016] The reflector body 2 is a structure having a predetermined thickness, in which the reflective portion 3 and the recessed portion 4 are molded integrally on both sides. The material constituting the reflector body 2 is, for example, a foamed synthetic resin such as a polyolefin resin, such as polystyrene, polyethylene, or polypropylene. In this embodiment, expanded polystyrene (EPS (expanded polystyrene)) is used. The raw material, polystyrene, is colorless and transparent, but the molded body formed by foaming its particles (beads) has a white appearance. Furthermore, since the expanded polystyrene is formed by foaming the beads and then thermoforming them in a mold of a predetermined shape, the surfaces of the molded body, i.e., the reflector body 2 and its reflective portion 3, are not covered with a resin sheet or the like, and the unevenness caused by the foamed beads constituting the foamed resin of the reflector body 2 is exposed. In this embodiment, the foaming ratio of the foamed resin of the reflector body 2 is set to 40 times.

[0017] The reflector body 2 has a circular outer peripheral shape and is, for example, a disk-shaped member with an outer diameter φ of the reflecting portion 3 on the upper surface of 800 to 1400 mm and a weight of 300 to 800 g. The upper surface of the reflector body 2 forms the reflecting portion 3. The convex curved surface 30 of the reflecting portion 3 protrudes most from the outer periphery at the center and is a gently convex surface formed with a curvature radius R of 1000 to 1500 mm, for example. The fruit tree reflector 1 shown in Figures 1 and 2 has an outer diameter φ of the reflecting portion 3 of 900 mm, a weight of the reflector body 2 of 541 g, and a curvature radius R of the convex curved surface 30 of 1234 mm.

[0018] The underside of the reflector body 2 has a smooth, annular peripheral surface 41 that forms the outer edge, and a recessed portion 4 is provided inside the peripheral surface 41. The recessed portion 4 is made up of a plurality of annular surfaces 42 that are parallel to the peripheral surface 41 and a plurality of inner wall surfaces 43 that are angled relative to the annular surfaces 42. The annular surfaces 42 and the inner wall surfaces 43 are arranged alternately, and the annular surfaces become smaller as they go inwards, thereby forming a stepped recessed portion 4 that is deepest in the center (see also Figure 2(d)).

[0019] By making the recessed portions 4 stepped in this way, the reflector body 2 has locally thicker portions than in a configuration in which the recessed portions 4 are curved surfaces corresponding to the convexly curved surfaces 30, thereby improving the strength of the reflector body 2. Furthermore, by having the recessed portions 4, when multiple reflector bodies 2 are stacked, the recessed portions 4 of the upper reflector body 2 overlap the convexly curved surfaces 30 of the lower reflector body 2, so multiple reflector bodies 2 can be stored in a space-saving manner.

[0020] The stepped corners of the recessed portion 4, i.e., the ridges between the toric surface 42 and the inner wall surface 43, are chamfered to give them a rounded shape. The stepped corners of the recessed portion 4, i.e., the valleys between the toric surface 42 and the inner wall surface 43, may also be chamfered. Sharp parts of foamed resin are brittle and easily breakable, so by chamfering these sharp parts, the recessed portion 4 and the reflector body 2 become less likely to break, thereby improving the durability of the fruit tree reflector 1.

[0021] The fruit tree reflector 1 has a reflector 3 with a convex curved surface 30 on its upper surface. The reflector 3 is white, based on the color of the foamed resin that constitutes the reflector body 2. The surface has a fine unevenness due to the uneven foamed beads. Therefore, light L irradiated onto the surface of the reflector 3 is diffusely reflected and scattered around. This reduces the amount of reflected light being locally irradiated, compared to conventional resin sheets with specular reflectivity. Furthermore, the fruit tree reflector 1 is a structure with a predetermined thickness, so its shape is fixed. Therefore, even when installed on a sloping, sunken ground, as with the fruit tree reflector 1A shown in Figure 3, the surface shape of the reflector 3 remains unchanged. Therefore, the fruit tree reflector 1 can appropriately diffuse and reflect reflected light, preventing damage such as burnt fruit.

[0022] Incidentally, the production of anthocyanins is necessary for apples to color, and it has been revealed that ultraviolet light with a wavelength of 290 to 380 nm and red light with a wavelength of 650 nm promote the production of anthocyanins. Therefore, tests were conducted on the surface characteristics and light reflection performance of several types of reflectors for fruit trees, including the reflector for fruit trees 1 of this embodiment. The samples were an EPS molded body with an expansion ratio of 40 times (Example 1), an EPS molded body with an expansion ratio of 60 times (Comparative Example 1), an EPS molded body with an expansion ratio of 60 times, and an EPS molded body with an expansion ratio of 60 times and a 0.5 mm thick film. EVA The sheet was laminated (Comparative Example 2), silver (aluminum vapor deposition) sheet (Comparative Example 3), and white ( polyester Using the sheet (Comparative Example 4), the reflectance for each wavelength was measured using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation).

[0023] Figure 4 shows the results of the reflection performance test. The silver sheet (Comparative Example 3) had low reflectance in all wavelength ranges. The silver sheet's aluminum film thickness vapor-deposited on the sheet surface was thin, allowing some light to pass through the sheet, which is thought to have resulted in unexpectedly low reflection performance. The white sheet (Comparative Example 4) had very high UV reflectance, but its reflectance for red light at a wavelength of 650 nm was slightly reduced. Regarding the EPS molded bodies, the 40x EPS molded body (Example 1) exhibited higher reflection performance for both UV and red light than the 60x EPS molded body (Comparative Example 1) and the laminated body (Comparative Example 2). In particular, the 40x EPS molded body had approximately 20% higher UV reflectance than the 60x EPS molded body. These results suggest that the expansion ratio of the foamed resin of the reflector body 2 is preferably less than 60x. By setting the expansion ratio of the foam resin to less than 60 times, the reflector plate for fruit trees 1 is given an appropriate weight, making it less likely to be blown away by the wind.

[0024] It is believed that as the expansion ratio of the foamed resin increases, light irradiated onto the surface of the molded body is more easily captured within the foamed beads, and some of the light captured within the foamed beads is not extracted to the outside, resulting in a decrease in reflectivity. However, if the expansion ratio of the foamed resin is reduced to increase reflectivity, a large amount of resin material is required to mold a fruit tree reflector 1 of a given size, which not only increases manufacturing costs but also makes the fruit tree reflector 1 unnecessarily heavy, making it difficult to install and carry. For this reason, it is preferable that the expansion ratio of the foamed resin of the reflector body 2 be 30 times or more.

[0025] If the expansion ratio of the foam resin of the reflector body 2 is 30 times or more, it will not be excessively heavy when carried. If the outer diameter φ of the reflector body 2 is 800 to 1400 mm, its weight is preferably 300 to 800 g. By setting the size and weight within these ranges, the fruit tree reflector 1 can be carried easily by a single worker and is also prevented from being blown away by the wind after installation. Therefore, the worker can easily install the fruit tree reflector 1.

[0026] Furthermore, the fruit tree reflector 1 of this embodiment has a convex curved surface 30 on the reflecting portion 3, and the radius of curvature R of the convex curved surface 30 is 1000 to 1500 mm. Here, FIG. 5(a) shows the results of a wind tunnel test in which a crosswind of 20 m / s was blown onto the fruit tree reflector 1 of the above embodiment using a large electric fan. As shown in the figure, the fruit tree reflector 1 was not blown away by the wind. On the other hand, when a crosswind of 20 m / s was blown onto a flat 900 mm square foamed resin plate as described above, the 900 mm square foamed resin plate was blown away, as shown in FIG. 5(b). As such, the fruit tree reflector 1 of this embodiment allows wind to flow along the convex curved surface 30, making it less likely to be blown away by the wind. Furthermore, installation does not necessarily require pegging, making installation easy.

[0027] In the fruit tree reflector 1 of this embodiment, if the outer diameter φ of the reflecting portion 3 is 800 to 1400 mm, the radius of curvature R of the convexly curved surface 30 is preferably 1000 to 1500 mm. If the radius of curvature R is 1000 or less, the protruding height of the convexly curved surface 30 becomes too high, making it susceptible to crosswinds and causing unnecessary reflection of light in the peripheral direction, which is undesirable. On the other hand, if the radius of curvature R is 1500 or more, the reflecting portion 3 becomes too flat, preventing effective flow of crosswinds and preventing adequate dispersion and reflection of light, which is undesirable.

[0028] Figures 6(a) to 6(d) show side views of a fruit tree reflector 1 according to a modification of the above embodiment. Figure 6(a) is a side view showing an example of a configuration with an outer diameter of 800 mm and a convexly curved surface with a radius of curvature R of 1000 mm. Figure 6(b) is a side view showing an example of a configuration with an outer diameter of 800 mm and a convexly curved surface with a radius of curvature R of 1500 mm. Figure 6(c) is a side view showing an example of a configuration with an outer diameter of 1400 mm and a convexly curved surface with a radius of curvature R of 1000 mm. Figure 6(d) is a side view showing an example of a configuration with an outer diameter of 1400 mm and a convexly curved surface with a radius of curvature R of 1500 mm. By setting the reflecting portion 3 to these outer diameters φ and radius of curvature R, the fruit tree reflector 1 can be prevented from being blown away by wind. Furthermore, by setting the foaming ratio of the foam resin of the reflector body 2 and the weight of the reflector body 2 as described above, it is possible to more effectively reduce the resistance to being blown away by wind.

[0029] The present invention is not limited to the configuration of the above embodiment, and various modifications are possible within the scope of the invention. In the above embodiment, the outer shape of the reflector body 2 is circular, but a polygonal shape similar to a circle, such as a hexagon, may also be used. Furthermore, although the above embodiment has been described as not requiring peg fastening, this does not exclude peg fastening. For example, the reflector body 2 may be provided with insertion holes for peg fastening in anticipation of use in areas with strong winds. [Explanation of symbols]

[0030] 1. Fruit tree reflector 2 Reflector body 3 Reflector 30 curved surfaces 4 Concave part FT Fruit Trees

Claims

1. The reflector is made of a foam resin and has a reflecting portion provided on one side of a disc-shaped reflector body. the reflecting portion has a white convex curved surface that is most protruding in the center, A reflector for fruit trees, characterized in that the outer diameter φ of the reflecting portion is 800 to 1400 mm, and the weight of the reflector body is 300 to 800 g.

2. 2. The reflector for fruit trees according to claim 1, wherein the radius of curvature R of the convex curved surface is 1000 to 1500 mm.

3. 3. The fruit tree reflector according to claim 1, wherein the reflecting portion has exposed on its surface irregularities resulting from foam beads constituting the foam resin of the reflector body.

4. A fruit tree reflector as described in claim 1 or claim 2, characterized in that the other surface of the reflector body opposite to the surface on which the reflective portion is provided has a stepped concave portion that is deepest in the center.

5. 5. The reflector for fruit trees according to claim 4, wherein the stepped corners of the recessed portion are chamfered to be rounded.

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