JP2018057275A - Agricultural greenhouse using double translucent film or double translucent plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agricultural greenhouse using a double translucent film or a double translucent plate that improves light transmissivity of the entire double translucent film, and reduces a region blocked by a panel frame portion at the same time.SOLUTION: Out of a translucent film or a translucent plate forming an air heat insulating layer, an inside surface of a greenhouse made from a translucent film or a translucent plate which is positioned outside the greenhouse has a plurality of ridges or grooves which are constituted of a scalene triangular cross section formed by an inclined plane having an angle of inclination from 5 degrees to 45 degrees and an inclined plane having an angle of inclination from 30 degrees to 85 degrees.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a structure of covering with a double translucent film or translucent plate used for enhancing heat retention in an agricultural greenhouse. A film or a plate differs only in thickness and hardness, and there is no difference in the functional aspect of blocking air and allowing light to pass therethrough. In the present specification, when the expression “film” is used, "Is also included.

  Agricultural greenhouses are high prices by spreading transparent vinyl film on a frame made of metal, etc., confining solar heat and keeping the house warm, promoting crop growth and shifting the harvest time. In the case of a single film, the temperature inside the house at night falls to almost the same as the outside temperature due to the heat conduction of the film, and these aims are not fully realized. It was. Therefore, two films are spread and spread, and an air layer of a certain thickness is provided between them, so that the air between the two films is used as a heat insulating layer to construct a greenhouse with good heat retention. Yes. As the prior art, as disclosed in Patent Document 1, a method for forming a heat insulating layer by providing a film fastening member twice and stretching each film in order to stretch a double film, and Patent Document 2 There is a method in which a heat insulating layer is formed by blowing air with an electric fan between double films, Patent Document 3 in which a panel in which a double film is stretched in advance on a frame having a certain thickness is attached to the roof surface of an agricultural house (FIGS. 1 and 2).

Japanese Patent Laid-Open No. 2008-5798 JP 2012-75405 A Japanese Patent Application No. 2013-16997

Agricultural houses using these double translucent films have very good heat retention, but the amount of light that can be taken into the house is reduced, so the amount of photosynthesis is reduced and the yield is high even if the temperature can be secured. There was a problem that it decreased or became vulnerable to pests.
There are two major factors. The first factor is that the light transmittance decreases due to Fresnel reflected light on a total of four refracting surfaces, two light transmissive films. In particular, in the winter season when the solar altitude is low, the angle of incidence on the translucent film is increased, so that the Fresnel reflectivity is increased and the light transmittance is significantly decreased. The light transmittance of the double light-transmitting film is only 30% when the light incident angle θ1 = 75 °, assuming a winter season, using a light-transmitting film having a refractive index n = 1.52 (polyolefin special film for agriculture). (FIG. 5).
The second factor is a structural material for maintaining the distance between the double light-transmitting films when using a panel in which the double light-transmitting films are stretched or when providing a double light-transmitting film using a film fastening member or the like. The amount of light is reduced due to the shadows. The frame for keeping the distance between the double light-transmitting films has a constant frame height (with a panel thickness) that can ensure heat insulation with respect to the frame width (W or L1 in FIG. 2) in order to reduce the light shielding area while maintaining rigidity. Corresponding: It is composed of the structure of t) in FIG. 2, but the influence of the panel thickness is greater in the winter season when the solar altitude is low than in the season when the solar altitude is high. The region D where the light beam is blocked by the frame is D = t × tan θ1 assuming that the light-transmitting film thickness is sufficiently thin with respect to the panel thickness t and the light incident angle θ1 with respect to the light-transmitting film surface. As an example, when the panel thickness is t = 38 mm, D = 141 mm is reached when the light incident angle θ1 = 75 ° assuming the winter season, and 14% when the distance between the frame of the panel (panel width W) is 1 m. The amount of light is reduced (FIG. 3).

  The light angle is controlled by forming a prism-like fine shape having an unequal triangular shape on the inner surface of the light-transmitting film located outside the double light-transmitting film, and among all four refracting surfaces In addition to increasing the light transmittance of the entire double light transmissive film by reducing the Fresnel reflectivity on the refracting surface by reducing the incident angle on the three refracting surfaces after the second refracting surface, the light is blocked by the panel frame portion. The problem is solved by simultaneously reducing the area.

  When this technology is used, the warmth of the house is improved by the double translucent film and the light intensity in the house is maintained at a high level in winter. Since the environment can be realized and the yield can be maintained at a high level, it is very useful in agricultural management, and it is possible to operate a facility horticulture that is meaningful from the viewpoint of the global environment such as global warming.

Example of applying a double translucent film panel structure to the ceiling of a flat-type house The perspective view of the panel member of the ceiling part in FIG. The figure which shows how a light ray advances in the double translucent film of a prior art The figure which shows how a light ray advances when it has a fine prism shape in the inner surface of the translucent film located in the outer side of a house by this invention The figure which shows the change (in the case of the polyolefin special film for agriculture) of the light quantity which can be taken into the house by the incident angle of a light beam The figure which shows how to advance the sunlight ray according to this invention for every season (in the case of polyolefin special film for agriculture A = 15 ° B = 45 °) An example in which a prism of A = 15 ° is provided inside the outer light-transmitting film of the double light-transmitting film, and a prism of A = 15 ° is provided inside the inner light-transmitting film. An example in which a prism of A1 = 8 ° is provided outside the outer light-transmitting film of the double light-transmitting film, and a prism of A1 = 20 ° is provided inside the outer light-transmitting film. The figure which shows the change (in the case of a fluorine film) of the quantity of light which can be taken into the house by the incident angle of a light Example of rounded corners of unequal triangular triangles or groove corners Example of a house constructed in the depth direction from north to south Example of a house constructed in the east-west depth direction An example in which the ridges or grooves of an unequal triangular cross section are line segments composed of short straight lines and these are arranged in a staggered manner An example in which the ridges or grooves of an unequal triangular cross section are line segments composed of short gentle curves, and these are arranged in a staggered manner An example of a zigzag pattern in which the ridges or grooves of an unequal triangular cross section repeat two angles alternately Example of corrugated pattern composed of loose curves in the shape of ridges or grooves of unequal triangular section An example in which ridges or grooves of a plurality of unequal triangular cross sections formed in parallel are formed by ridges or grooves in two directions having angles with each other. The figure which expressed both the ridgeline and the groove line in FIG. FIG. An example in which the ridges or grooves of a plurality of unequal triangular cross sections formed in parallel are formed by ridges or grooves in three directions having angles with each other. The figure which expressed both the ridgeline and the groove line in FIG. And its partially enlarged sectional view Table showing an example of calculation of the light refraction angle according to the present invention when using an agricultural polyolefin-based special film

Using an agricultural polyolefin special film having a refractive index of n = 1.52, a fine prism shape of A = 15 ° is formed on the inner surface of the outer light-transmitting film, and the inner light-transmitting film is an ordinary light-transmitting film. When used, the light transmittance into the house for a light beam with an incident angle θ1 = 75 ° assuming a winter season is 61%, which is about twice that of the conventional light transmittance of 30% (FIG. 5).
The region D where the light ray is blocked is assumed to be D = when the film thickness is sufficiently thin with respect to the panel thickness t, the light incident angle θ1 with respect to the film surface, and the light ray angle θ3 of the transmitted light of the first light transmitting film. t × tan θ3. As an example, when the panel thickness is t = 38 mm, θ3 = 54 ° and D = 52 mm when the incident angle θ1 = 75 ° in winter is assumed, which is a significant reduction compared to the conventional 141 mm (FIG. 4).

Among the double translucent films, not only the translucent film located outside the house but also the translucent film inside the house, the slope of the house inner surface having an inclination angle of 5 to 45 degrees, and the inclination angle of 30 degrees A plurality of ridges or grooves constituted by an unequal triangular cross section with a slope having 85 degrees may be provided.
When both of the two light-transmitting films are made of an agricultural polyolefin special film having a refractive index n = 1.52 and a fine prism shape of A = 15 ° is formed on the inner side, an incident angle θ1 = 75 ° is assumed for winter. The light transmittance of the light beam into the house is 63%, which is further improved than the light transmittance of 61% in the case where a plurality of ridges or grooves constituted by an unequal triangular cross section is provided only on the outer light-transmitting film. (FIG. 7).

In the case of a double translucent film according to the prior art using a fluorine film having a refractive index n = 1.34, the light transmittance into the house for a light beam with an incident angle θ1 = 75 ° assuming a winter season is 38%.
When the fine prism shape of A1 = 8 ° is formed on the outer surface of the outer light-transmitting film and the fine prism shape of A2 = 20 ° is formed on the inner surface of the outer light-transmitting film, the light transmittance is 73%, The light transmittance is further improved from 70% when the outer surface of the light-transmitting film is flat and the fine prism shape of A = 20 ° is formed on the inner surface of the outer light-transmitting film (FIGS. 8 and 9).
In FIG. 8, the inner surface of the light-transmitting film 4 located outside the house is an inclined surface having an inclination angle A2 of 5 to 45 degrees, and the outer surface of the light-transmitting film 4 located outside the house. The surface is preferably an inclined surface having an inclination angle A1 of 2 to 45 degrees and an angle smaller than the inner surface of the house.

  In Example 1 to Example 3, the height of the unequal triangular shape of the translucent film or translucent plate having an unequal triangular shape is 1/50 to 1/2 of the average thickness of the translucent film or translucent plate. By doing so, it is possible to obtain effective refractive characteristics while maintaining the strength of the translucent film.

In Example 1 to Example 3, an effective refraction characteristic is obtained while maintaining the strength of the translucent film by making the corner of the unequal triangular triangle or the corner of the groove rounded. (FIG. 10).
Further, in this case, the scattered light generated in the rounded portion enters the house room, and it becomes difficult to produce a shadow, so the amount of light received as a crop community increases.

In Example 1 to Example 3, a fine structure composed of fine concave portions or convex portions having any one of a pyramidal shape, a hemispherical shape, a columnar shape, or a parabolic shape on one side or both sides of the translucent film. By providing the pattern, the light transmittance of the translucent film can be further increased.
In general, the fine pattern has a pitch of 30 nm to 5 μm, a width of a concave or convex portion of 30 nm to 5 μm, and an aspect ratio of the concave or convex portion of 0.2 to 15.

  Of the double light-transmitting films of Examples 1 to 3, the light-transmitting film located outside the house is a fluorine film having good weather resistance, and an inexpensive agricultural special polyolefin-based film is used as the light-transmitting film inside the house. By using it, it is possible to realize an agricultural house that has a long life, that is, does not require frequent film replacement at low cost.

  In general, a house constructed in the depth direction from north to south tends to have a larger incident angle of the sun than a house constructed in the depth direction from east to west, and the difference is particularly noticeable in winter. Even in a house built in this direction, the light transmittance into the house can be increased (FIGS. 11 and 12).

  In Example 1 to Example 3, the ridges or grooves of the unequal triangular cross section are not a straight line extending across both ends of the translucent film, but a short line segment or a loose curve divided in the middle, or two When the wave pattern is composed of zigzag patterns or loose curves that repeat the angles alternately, the tear strength of the translucent film improves, and the scattered light from the divided end faces and the refracting surface facing various directions As a result, light rays are directed in various directions, and it becomes difficult for shadows to appear in the house, so that the amount of light received as a crop community increases (FIGS. 13 to 16).

In Example 1 to Example 3, when the ridges or grooves of a plurality of unequal triangular cross-sections formed in parallel are constituted by two-direction ridges or grooves or three-direction ridges or grooves having an angle with each other, It is possible to prevent a decrease in the effect due to the sun direction.
When it is constituted by two-direction ridges or grooves, it becomes a quadrangular pyramid protrusion or depression, and when it is constituted by three-direction ridges or grooves, it becomes a triangular pyramid protrusion or depression.
In this case as well, light beams directed in various directions enter the house, and the same effects as those of the ninth embodiment can be obtained at the same time (FIGS. 17 to 20).

  In any of the embodiments described above, the same effect can be obtained regardless of the material of the translucent film or translucent plate, such as a fluorine film, a polyolefin special film, a polycarbonate plate, or an acrylic plate.

DESCRIPTION OF SYMBOLS 1 Roof panel member 2 Agricultural house structural member 3 Panel frame member 4 Translucent film member outside agricultural house 5 Translucent film member inside agricultural house 6 Ridge of unequal triangular cross section

Claims (7)

An agricultural house having a double translucent film or a double translucent plate forming an air insulation layer,
Of the light-transmitting film or the light-transmitting plate, the inner surface of the light-transmitting film or the light-transmitting plate located on the outside of the house is inclined with an inclination angle of 5 to 45 degrees, Agriculture using a double translucent film or a double translucent plate characterized by having a plurality of ridges or grooves composed of an unequal triangular cross section with a slope having an angle of 30 to 85 degrees For house.   An unequal side in which the outer surface of the light-transmitting film or the light-transmitting plate located on the outer side of the house has a slope with an inclination angle of 2 to 45 degrees and a smaller angle than the inner surface of the house. The agricultural house using the double light-transmitting film or the double light-transmitting plate according to claim 1, wherein the house has a plurality of ridges or grooves each having a triangular cross section.   The ridge or groove of the unequal triangular cross section is a straight line, the straight direction is arranged in the east-west direction on the roof surface of the house, and the slope having the inclination angle of 30 degrees to 85 degrees is arranged in the south direction. An agricultural house using the double light-transmitting film or the double light-transmitting plate according to claim 1 or 2.   The ridge or groove of the unequal triangular cross section is constituted by a line segment or a curve divided in the middle of the translucent film or the translucent plate instead of a straight line extending over both ends of the translucent film or translucent plate. Or the agricultural house using the double translucent film or double translucent board of Claim 2.   The double edge according to claim 1 or 2, wherein ridges or grooves of the plurality of unequal triangular cross sections formed in parallel are formed in two or three directions having an angle with each other. Agricultural house using translucent film or double translucent plate.   The double light transmission according to claim 1 or 2, wherein a roof surface constituted by the double light transmission film or the double light transmission plate has an independent panel structure. Agricultural house using film or double translucent plate.   Of the light-transmitting film or the light-transmitting plate, the inner surface of the light-transmitting film or the light-transmitting plate located on the inner side of the house has a slope having an inclination angle of 5 degrees to 45 degrees, 2. The double translucent film or double double crystal according to claim 1, comprising a plurality of ridges or grooves each having an unequal triangular cross section with a slope having an inclination angle of 30 to 85 degrees. Agricultural house using translucent plates.