WO2001065920A1

WO2001065920A1 - A panel for green-house and a ventilation system using the same

Info

Publication number: WO2001065920A1
Application number: PCT/KR2001/000251
Authority: WO
Inventors: In Hak Yoon; Jin-Young Kim; Hee Chun; Hyun-Hwan Kim; Si Young Lee
Original assignee: Korea Rural Development Administration
Current assignee: Korea Rural Development Administration
Priority date: 2000-02-22
Filing date: 2001-02-20
Publication date: 2001-09-13
Anticipated expiration: 2002-08-22
Also published as: KR100369925B1; KR20000024582A; AU2001236160A1; JP2004508008A

Abstract

The present invention provides a ventilation system for a greenhouse. The ventilation system comprises fixed and foldable panels each consisting of frames, cross-shaped bars and a two-fold cover for increasing the insulation performance of the greenhouse and facilitating the construction and maintenance of the greenhouse due to easy assembly, panes each consisting of foldable panel having divided halves foldable around a hinge member and situated the ceiling and sidewall of the greenhouse, and drive means for selectively opening and closing the panes. Accordingly, when panes are opened, indoor air of high temperature flows out of the greenhouse through the fully opened portion and outdoor air of low temperature flows into the greenhouse through the laterally opened portions.

Description

A PANEL FOR GREEN-HOUSE AND A VENTILATION SYSTEM USING THE SAME

Technical Field

The present invention relates generally to a greenhouse, and more particularly to a panel for a greenhouse and ventilation system using the same, which is fabricated by frames and cross-shaped bars.

Background Art

Generally, in order to cultivate agricultural products, such as vegetables, flowering plants or fruit trees in large quantities, large-sized vinyl houses and glass houses are installed and utilized. In the meantime, the agricultural products, such as vegetables, flowering plants, etc. require an appropriate temperature and appropriate lighting in view of their growth characteristics, so in installing and utilizing greenhouses ventilation should be carried out to maintain appropriate lighting and keep an indoor temperature at an appropriate level. On the one hand, if the light is shielded to maintain an appropriate temperature when outdoor air is hot, lighting is deteriorated. On the other hand, if sufficient lighting is ensured, it is difficult to maintain an appropriate temperature. In both cases, hindrance to the growth of the agricultural products is caused. Accordingly, there is employed a technique in which appropriate light is ensured and an appropriate temperature is maintained to help the growth of the agricultural products by providing a greenhouse with a window and ventilating the greenhouse.

A general window for a greenhouse adopts a typical hinge technique by which one side end of the window is rotated around the other side end. However, in view of the structural characteristics of the greenhouse, it is difficult that the ratio of opening created by the windows exceeds 12 to 20% of the entire surface area of the greenhouse, so it is almost impossible to maintain a required indoor temperature. An appropriate temperature required for the growth of agricultural products is about in the range of 25 to 30°C, though it is somewhat different according to the kinds of agricultural products. In summer, the indoor temperature of a greenhouse reaches about 70 to 80°C when the greenhouse is closed. Additionally, even though its windows are opened, the opened area of the greenhouse is relatively small, and the indoor temperature of the greenhouse reaches about 40 to 50°C because of the insufficient inflow and outflow of outdoor and indoor air according to the structure of the windows. In fact, it is almost impossible to cultivate the agricultural products.

In order to solve such a problem, in the past the indoor, during hot seasons temperature of a greenhouse is forcibly lowered using a sprinkler, a fan or an air conditioner. However, this imposes a heavy burden on farm households due to high costs, and is not available to a large-sized greenhouse.

In addition, when outdoor air is cold, a greenhouse is constructed by overlapping two or three sheets of vinyl so as to reduce the loss of heat. In this case, the construction and maintenance of the greenhouse is inconvenient, high costs are incurred to cultivate agricultural products, and an excessive increase in temperature is brought about when outdoor air is hot.

Meanwhile, the above-described problems occur in facilities, such as a factory, a cattle shed, etc.

Disclosure ofthe Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object ofthe present invention is to provide a ventilation system for a greenhouse, which is capable of withstanding wind and considerably increases the ratio of opening of the greenhouse, thereby naturally ventilating so as to keep the indoor temperature of the greenhouse appropriate for the growth of agricultural products and livestock during hot seasons without cooling means.

Another object of the present invention is to provide a ventilation system for a greenhouse, which is capable of allowing the inflow and outflow of indoor and outdoor air to be smoothly carried out.

A further object ofthe present invention is to provide an assembly panel for a greenhouse, which has superior insulation performance and facilitates the construction and maintenance ofa greenhouse.

In order to accomplish the above object, the present invention provides a panel for a greenhouse, comprising: an inner frame provided with a plurality of engaging slits at appropriate intervals on its inner surface, a fixing slit in its longitudinal direction on its outer surface, and an opening in its center; a plurality of cross-shaped bars arranged in the form of lattices in the opening of the inner frame with both ends thereof inserted into the engaging slits; two covers attached to upper and lower surfaces ofthe inner frame to seal the opening; and an outer frame provided in its inner portion with an engaging channel and engaged with the inner frame to cover the peripheral edges ofthe covers.

In accordance with a feature of the panel of the present invention, the covers are made of one or more soft transparent sheets and are inserted into the fixing slit of the inner frame by a wedge bar.

In accordance with another preferable feature of the panel of the present invention, the cover is made of a glass plate, and the peripheral edges of the glass cover is interposed between the inner and outer frames and fixedly attached to the frames by a bonding agent.

In the meantime, a ventilation system for a greenhouse, comprises: one or more foldable panels each consisting of at least two body halves which are connected to each other by a folding means for pivotal movement of the one body half; one or more guides attached to at least one edge of the another body half; one or more panes for each foldable panel having one or more guide rails attached thereto and combined with the guide for guiding the folding movement thereof; drive means for opening or closing the panes by moving one of body halves of the foldable panels with another body half being pushed or pulled, resulting in pivotal movement ofthe body halves on the folding means.

In accordance with a feather ofthe ventilation system ofthe present invention, the drive means comprises a rotating shaft provided with a pinion, a rack engaged with the pinion, a guiding holder, a guiding holder rotatably fitted around the rotating shaft for maintaining the engagement ofthe rack and the pinion and guiding the rack during its movement, and a motor for normal or reverse rotating ofthe rotating shaft.

In accordance with another feather of the ventilation system of the present invention, the fixed and foldable panels are equal in width, or greater in width than the fixed panels.

Brief Description ofthe Drawings

Fig. 1 is a perspective view showing a panel for a greenhouse employing vinyl in accordance with an embodiment ofthe present invention; Fig. 2 is a cross section taken along line A-A of Fig. 1; Fig. 3 is an enlarged view showing the principal portion of Fig. 2;

Fig. 4 is an exploded view of Fig. 3;

Fig. 5 is a cross section corresponding to Fig. 3 and showing a panel for a greenhouse employing hard material such as glass; Figs. 6a and 6b are front and side views showing a panel for a greenhouse in accordance with another embodiment ofthe present invention, respectively;

Fig. 7 is a cross section taken along line B-B of Fig. 6a;

Fig. 8 is a cross section taken along line C-C of Fig. 6a;

Fig. 9 is a schematic perspective view showing a ventilation system for a greenhouse employing the panels for a greenhouse in accordance with the present invention;

Fig. 10 is a schematic cross section of Fig. 9;

Fig. 11 is a view showing the operation of the foldable panel viewed from line D-D of Fig. 9; Figs. 12a to 12c are front views showing

Fig. 13 is an exploded perspective view showing the foldable panel of Fig. 9;

Fig. 14 is a rear assembly view of Fig. 13;

Fig. 15 is a cross section taken along line E-E of Fig. 14;

Figs. 16a and 16b are cross sections showing the operation of the ventilation system of Fig. 13; and

Fig. 17 is a partial rear view showing a greenhouse to which the ventilation system of Fig. 17 is applied.

Best Mode for Carrying Out the Invention

The detailed features and advantages of the present invention will be understood from the following description of preferred embodiments with reference to accompanying drawings.

First of all, a fixed panel 10 of a panel 1 for greenhouse is described by its embodiment. In Figs. 1 to 4 in which the fixed panel 10 of the present invention is illustrated, the fixed panel 10 comprises an inner frame 20 having a central opening 25 and a rectangular shape, a plurality of cross-shaped bars 30 disposed in the central opening 25 of the inner frame 20 in the arrangement of a lattice, two covers 40 form an air layer by being fixedly attached to both sides of the inner frame 20 and sealing the opening 25, and an outer frame 50 engaged with the outer surface of the inner frame 20 to surround the peripheral edges ofthe outer surfaces ofthe covers 40.

The inner frame 20 is constructed by assembling or welding four rectangular bars together. The hollow portion in the inner frame 20 is divided into inner and outer hollow portions 22 and 23 by a baffle 24. A plurality of engaging slits 26 are formed on the inner surface of the inner frame 20 at regular intervals to be engaged with the cross-shaped bars 30. A fixing slit 27 is longitudinally formed on the outer surface ofthe inner frame 20 to lock the cover 40. The engaging slit 26 comprises a first slit 26a longitudinally formed on the inner surface of the inner frame 20 and second slits 26b regularly arranged to be perpendicular to the first slit 26a. This is because the cross-shaped bar 30 has a cross shape. Accordingly, the shape of the engaging slit 26 may be varied according to the shape ofthe bar 30.

In the meanwhile, when the cover 40, as an example, is made of soft material, such as vinyl sheet 41, the fixing slit 27 is employed to fix the outer edge ofthe vinyl sheet 41 while the vinyl sheet 41 is supported by a wedge bar 43. Two elastic plates 28 are inwardly formed along the edges of the fixing slit 27 that is brought into contact with the side surfaces ofthe wedge bar 43. Each ofthe cross-shaped bars 30 serves not only to maintain the shape of the fixed panel 10 but also to support the cover 40. The cross-shaped bar 30 may have any shape if it can perform its function. However, the cross-shaped bar 30 preferably has a cross-shaped section. The cross-shaped bars 30 are engaged with one another so as to be intersected with one another, so they form a lattice arrangement. Accordingly, each of two neighboring ribs 31 and 32 are formed to be larger than each of the other ribs 33 and 34 by the thickness of each rib, and a plurality of slits 35, 36 and 37 are regularly formed on the relatively long rib 31 and its neighboring ribs 32 and 34 to be engaged with another cross-shaped bar 30. This is to allow the upper and lower ends of each cross-shaped bar 30 to coincide with each other because the cross-shaped bar 30 is formed in the shape of a cross. As a result, the first slit 26a of the engaging slit 26 of the inner frame 20 has a width corresponding to double the thickness of each rib 31, 32, 33 or 34 ofthe cross-shaped bar 30.

In such a case, only the rib 31 ofthe cross-shaped bar 30 can be formed to be relatively long. However, in order to realize stable engagement by increasing the length of the portion of the cross-shaped bar 30 inserted into the engaging slit 26 of the inner frame 20, the rib 32 to be inserted into the engaging slit 26 ofthe inner frame 20 is formed to be relatively long together with the rib 31.

The cover 40 can be made of a variety of materials. Since a greenhouse 41 requires appropriate lighting, the cover 40 is made of a soft transparent sheet or transparent body such as a glass plate 42. For example, when the cover 40 is made of a vinyl sheet 41, the peripheral portion of the vinyl sheet 41 is inserted into and fixed in the fixing slit 27 ofthe inner frame 20 by the wedge bar 43, so an air layer is formed in the opening 25 of the inner frame 20. For ease of fabrication, the vinyl sheet 41 is formed in the form of a connected two-fold sheet to allow the inner frame 20 to be inserted into the vinyl sheet 41. An outer frame 50 is constructed by assembling front, rear, right and left bars together in the form of a rectangular frame. Each bar of the outer frame 50 has a channel-shaped cross section that is inwardly open. As a result, a continuous engaging channel, into which the inner frame 20 is inserted, is formed in the outer frame 50. Preferably, two opposed protrusions 52, which are elastically engaged with the inner periphery of the inner frame 20, are formed in the entrance of the engaging channel, that is, on the inner periphery ofthe inner surface ofthe outer frame 50. Two rainwater intercepting barriers 53 are formed on both edges of the side surface of the outer frame 51, that is, both edges of the surface of the outer frame 51 on which a plurality of panels are continuously arranged, so as to prevent rainwater from entering the interior of a greenhouse.

The inner and outer frames 20 and 50 and the cross-shaped bars 30 are preferably made of light metal or synthetic resin of high strength.

Next, the fabrication method of the panel for a greenhouse having such construction is described.

First of all, a plurality of cross-shaped bars 30 are assembled in the form of a lattice by engaging the cross-shaped bars 30 with one another using the slits 35, 36 and 37, the front, rear, left and right bars are connected to each other to allow the neighboring ends of each cross-shaped bar 30 to be inserted into corresponding engaging slits 26, and, thereafter, the neighboring ends of the bars are connected to each other.

Thereafter, the inner frame 20, into which the cross-shaped bars 30 are fitted, is surrounded by the barrel-shaped vinyl sheet 41, and two wedge bars 43 are inserted into the fixing slit 27 from the sides of the vinyl sheet 41. Thereby, the vinyl sheet 41 is held by the inner frame 20 while being tightly pulled by the wedge bars 43. At this time, the elastic plates 28 of the inner frame 20 are elastically deformed by the wedge bars 43, so the vinyl sheet 41 is securely held by the elastic plates 28. Subsequently, when the upper and lower wedge bars 43 are inserted into the fixing slit 27 after the upper and lower ends ofthe vinyl sheet 41 are fold around the inner frame 20, the upper and lower ends ofthe vinyl sheet 41 are inserted into the fixing slit 27 of the inner frame 20 by the wedge bars 43 and fixed in the fixing slit 27, thereby forming an air layer. In this state, the front, rear, right and left bars ofthe outer frame 50 are engaged with the outer surface ofthe inner frame 20. Thereby, the protrusions 52 formed on the inner ends of the inner surface of the inner frame 20 are elastically and fixedly engaged with the inner ends of the inner frame 20. Subsequently, the neighboring ends ofthe bars are attached to one another, resulting in the fabrication of a panel.

Additionally, in Fig. 5, there is illustrated a state in which a glass plate 42 instead of a vinyl sheet 41 is employed as the cover 40. In this case, two glass plates 42 are disposed on the side surfaces ofthe inner frame 20, the front, rear, right and left bars of the outer frame 50 are fixedly attached to each other to cover the peripheral edges of the two glass plates 42, and the inner ends of the outer frame 50 and the two glass plates 42 are fixedly attached to each other by a bonding agent, thereby forming a panel. Accordingly, in the case of adopting the glass plate 42 as the cover 40, the need for the wedge bar 43 is obviated. In the meantime, in Figs. 6 to 8, there is illustrated the foldable panel 60 for a greenhouse. This foldable panel 60 has the same basic construction including the inner frame, the cross-shaped bar, the cover and the outer frame as those for the fixed panel 10. The same reference numerals are assigned to the same or similar components, and the detailed description ofthe components are omitted. As shown in the drawings, the foldable panel 60 is comprised of two body halves 61 and 62 that are separated from each other. The foldable panel 60 is constructed by foldably attaching the body halves 61 and 62 to each other by a hinge 63. Two pairs of cover flanges 65 and 66 are provided on the side ends of the body halves 61 and 62, that is, both sides ofthe body halves 61 and 62 arranged to construct a greenhouse, to cover the peripheral edges ofthe fixed panels 10. The cover flanges 64 serve to prevent rainwater from infiltrating the interior of a greenhouse through the gap between each ofthe fixed panels 10 and each of the foldable panels 60. Each of the cover flanges 64 is formed to cover at least each of the rainwater intercepting barriers 53.

Additionally, as depicted in Fig. 8, in order to securely prevent the infiltration of rainwater, packings 67 can be provided on the lower surfaces of the outer portions ofthe cover flanges 65 and 66 together with the cover flanges 65 and 66 to come into contact with the upper surfaces of the fixed panels 10 and, thereby, keep airtightness between each ofthe cover flanges 65 and 66 and each ofthe fixed panels 10.

In addition, since the foldable panel 60 is formed by connecting the body halves 61 and 62 to each other by the hinge 63, the gaps between the body halves 61 and 62 should be securely stopped up. To this end, as shown in Fig. 7, an additional cover flange 68 is provided on the lower end of the upper surface of the upper body half 61 to cover the upper end of the upper surface of the lower body half 62, and a second rainwater intercepting barrier 69 is provided on the upper end of the upper surface ofthe lower body half 62 to be situated under the second cover flange 68.

Each ofthe panels 10 and 60 for a prefab greenhouse according to the present invention has an air layer between its upper and lower covers 40, so its insulating performance is considerably increased in comparison with a conventional greenhouse employing a plurality of sheets of vinyl. The above-described structure ofthe panels 10 and 60 facilitates the construction and maintenance ofa greenhouse.

Meanwhile, Figs. 9 to 11 illustrate a ventilation system for a greenhouse that is constructed using the panels ofthe present invention. The ventilation system for a greenhouse according to the present invention is constructed by alternately arranging one or more foldable panels 60. This structure may be applied to only the ceiling of a greenhouse, or the ceiling and sidewalls of a greenhouse if necessary. The fixed panels 10 are fixedly and regularly attached to the framework of a greenhouse, for example, via C-shaped steel, while the foldable panels 60 are foldably attached to the framework by movable support means.

In such a case, as shown by dotted arrows in Fig. 11, in a normal state the cover flanges 65 of the foldable panels 60 cover the peripheral edges of the upper surfaces of the fixed panels 60. Each of the cover flanges 65 is provided with a packing 67 to be brought into contact with the fixed panel 10, and the rainwater intercepting barrier 53 is formed on the upper surface of the fixed panel 10 to be inwardly extended over the packing 67, thereby preventing rainwater from infiltrating through the gap between the panels 10 and 60 when the panels 10 and 60 are closed. The one-dot chain lines of the drawing indicate the state in which the foldable panel 60 is opened.

As a result, the greenhouse 100 according to the present invention has an opening ratio of about 50%. The opening ratio of the greenhouse 100 can be increased to 85% at a maximum by controlling the widths of the fixed and foldable panels 10 and 60 within the given entire size of the greenhouse. That is, since the ventilation system for a greenhouse of the present invention is constructed by alternately arranging the fixed panels 10 and the foldable panels 60, the greenhouse 100 has an opening ratio of about 50% when the width LI of the foldable panel and the width L of each fixed panel 10 are equal as shown in Fig. 12a, and has an increased opening ratio when the width LI' of the foldable panel 60 is two times as large as the width L' ofthe fixed panel 10 as shown in Fig. 12b or the width LI" ofthe foldable panel 60 is four times as large as the width L" ofthe fixed panel 10 as shown in Fig. 12c.

In such a case, an increase in the width of the foldable panel 60 corresponds to the width of the fixed panel 10. The width LI, LI' or L' of the foldable penal 60 is set within about 2m. The reason for this is that if not, strength against a strong wind is considerably reduced when the foldable panel 60 is opened, that is, that the structural stability ofthe greenhouse is achieved. As a result, in order to increase the opening ratio of the greenhouse 100 it is preferable to appropriately set the width LI, LI ' or L" of the foldable panel 60 within the above-described range and increase the number ofthe foldable panels 60.

In addition, in the ventilation system for a greenhouse according to the present invention, the opening of a pane ofthe greenhouse is divided into two portions. That is, the upper portion of the opening is fully opened, while the lower portion of the opening is laterally opened, thereby increasing the opening ratio ofthe greenhouse 100 and allowing the inflow and outflow of indoor and outdoor air to be smooth and rapidly performed. That is, as shown in Fig. 9, indoor air of high temperature rapidly flows out ofthe greenhouse 100 through the upper fully opened portion ofthe opening and outdoor air of low temperature flows into the greenhouse 100 through the lower laterally opened portion of the opening. Accordingly, during hot seasons, the indoor temperature of the greenhouse 100 can be kept appropriate to the growth of agricultural products and the appropriate lighting can be maintained by natural ventilation without cooling means.

Meanwhile, in Figs. 13 to 15, there is illustrated an example of the drive and support means 70 that drives and supports the pane employing the foldable panel 60 in the ventilation system for a greenhouse according to the present invention. The drive and support means comprises hinge means for rotatably supporting the lower end of the foldable panel 60, the pane including guide means for guiding the foldable panel 60 during its folding operation, and drive means for selectively opening or closing the pane by properly folding the foldable panel 60 as occasion demands.

The hinge means comprises two hinge pins 71 formed on both ends of the lower end ofthe lower body half 62 ofthe foldable panel 60, and two hinge blocks 72 mounted on the framework 110 of the greenhouse 100 to be opposite to each other. The hinge pins are preferably mounted on the lower surface ofthe lower body half 62 ofthe foldable panel 60 to allow the foldable panel 60 to be situated on the same plane as that ofthe fixed panel 10. The guide means comprises two guide rails 73 situated beside the foldable panel 60 in parallel with the foldable panel 60 and two guides 77 mounted on both sides ofthe upper end of the upper body half 61 to be movably inserted into the guide rails 73. The guide rails 73 are mounted on the framework 110 of the greenhouse 100. Each ofthe guide rails 73 comprises two rail pipes 75 arranged in parallel with each other to form a rail slit 76 therebetween and two fixing blocks 74 for fixing and supporting the ends of the rail pipes 75. Further, a holding bend 75a is preferably formed on one of the rail pipes 75 to hold one of the guides 77 when the foldable panel 60 is extended. The holding bend 75a serves to securely and stably close the foldable panel 60 when the windows of the greenhouse 100 are closed. Each of the guides 77 comprises a bracket 78 provided with an inwardly projected connecting member 79 and attached to the lower surface ofthe upper body half 61 and a guide pin 80 rotatably attached at its one end to the end of the connecting member 79 and inserted at its other end into the rail slit 76 ofthe guide rail 73. As shown in Fig. 14, the connecting member 79 ofthe guide 77 is inwardly upwardly inclined to allow the foldable panel 60 to be smoothly bended. Alternatively, although not shown in the drawing, in the guide means each of the guide rails is provided with a guide channel and each ofthe guide pins is provided with a guide roller that can be engaged with the guide channel.

The drive means comprises a rotating shaft 81 provided with a pinion 82, a rack 84 engaged with the pinion 82, a guiding holder, a guiding holder rotatably fitted around the rotating shaft 81 for maintaining the engagement of the rack 84 and the pinion 82 and guiding the rack 84 during its movement, and a motor 88 for normal and reverse rotating of the rotating shaft 81. The rotating shaft 81 extends over said panels 60 provided with a pinion 82 and a rack 84 at regular intervals and operated by a single motor 88 at the same time. The rack 84 is rotatably attached at its one end to a portion near the bent portion of the foldable panel 60, for example, a hinge bracket 85 situated on the center of the upper portion of the lower surface of the lower body half 62. The guiding holder 86 can be constructed in one of a variety of shapes. For example, as shown in Fig. 13, the guiding holder 86 is U-shaped, and fitted around the rotating shaft 81 with its both ends surrounding both sides of the pinion 82. The guiding holder 86 is provided with a roller to be brought into sliding contact with the flat surface of the rack 84. In such a case, the pinion 82 is rotatably attached to the guiding holder 86. The pinion 82 and the rotating shaft 81may be attached to each other by a key (not shown).

In the meantime, although the drive means is not shown in the drawing, the drive means can be an actuator, such as a hydraulic or pneumatic cylinder as occasion demands.

Next, the operation in which the pane of the greenhouse 100 is selectively opened or closed by the drive and support means is described with reference to Figs. 16a and 16b. First of all, Fig. 15 shows the state in which the pane is closed by the extended foldable panel 60 when the greenhouse 100 is closed. In such a case, with reference to Fig. 10, the upper end of the foldable panel 60, that is, the upper end of the upper body half 61, enters the ridge of a roof 120 and the guide pin 80 mounted on the upper half 61 of the foldable panel 60 is positioned on the holding bend 75a formed on the rail pipe 75 of the guide rail 73, so the foldable panel 60 is securely closed, thereby preventing rainwater from entering the greenhouse 100.

In this state, when the greenhouse 100 is desired to be opened, the motor 88 is normally operated by the manipulation of an operation switch (not shown). As shown in Fig. 16a, the pinion 82 fitted around the rotating shaft 81 is rotated in the clockwise direction indicated by an arrow F in the drawing, and the rack 84 engaged with the pinion 82 is moved in the direction toward the outside of the greenhouse 100 indicated by an arrow G. Accordingly, the end of the rack 84 attached to the upper end of the lower body half 62 pushes the upper end of the lower body half 62 to the outside, so the body halves 61 and 62 are folded around the hinge 63. That is, as shown in the drawing, since the lower body half 62 of the foldable panel 60 is restrained to the framework 110 by the hinge pin 71 and the upper end o the upper half 61 connected to the lower body half 62 by the hinge 71 is downwardly moved along the guide rail 73 by the guide 77 attached to the lower body half 61, the body halves 61 and 62 are bent around the hinge 63.

In this case, the lower body half 62 is rotated around the hinge pin 71 in the counterclockwise direction H. The rack 84 is moved while being engaged with the pinion 82 by means ofthe guiding holder 86 that is fitted around the rotating shaft 81 and provided with the pinion 82. The guide roller 87 attached to the guiding holder 86 guides the surface ofthe rack 84 that is not engaged with the pinion 82.

Fig. 16b shows the state in which the guide 77 reaches the low end of the guide rail 73 and the pane is fully opened. The inflow and outflow of indoor and outdoor air are conducted through the opening of the foldable panel 60, so the ventilation ofthe greenhouse 100 is achieved.

The ventilation ofthe greenhouse is described in detail with reference to Figs. 9 and 10. When the pane is opened, air of high temperature occupying the upper portion of the interior of the greenhouse 100 is discharged from the interior of the greenhouse 100 in the direction indicated by dotted arrows through the fully opened portion ofthe pane and, at the same time, air of low temperature flows into the vacant space ofthe greenhouse 100 created by the discharge of the air of high temperature in the direction indicated by solid arrows through the laterally opened portions of the pane. As a result, the discharged air of high temperature and the entering air of low temperature form the natural circulation of air, so the outflow of indoor air and the inflow of outdoor air are smoothly carried out.

When the foldable panel is arranged in the sidewall of the greenhouse 100, the foldable panel creates the same effect as that of the foldable panel positioned on the ceiling ofthe greenhouse. When the greenhouse 100 is desired to be closed, the motor 88 is reversely operated by the operation switch. The closing operation of the foldable panel 60 is performed in the reverse order of the above-described opening operation. Finally, as shown in Fig. 15, the foldable panel 60 is extended, so the opening of the pane is closed, thereby closing the greenhouse 100. Meanwhile, the operation of the foldable panel 60 can be performed individually by an exclusive motor 88 assigned to the foldable panel 60. As shown in Fig. 17, a single rotating shaft 81' is formed to be long so as to take charge of a plurality of foldable panels 60, supported by a plurality of bearing blocks 83 and provided at regular intervals with a plurality of pinions 82, thereby allowing a single motor 88 to selectively open or close a plurality of panes by folding the foldable panels 60 at the same time. In such a case, when the greenhouse 100 is small-sized, all the foldable panels 60 situated on the same plane can be operated by a single motor 88; while when the greenhouse 100 is large-sized, it is preferable to divide the foldable panels 60 into groups and separately operate the groups.

Although the present invention is described with regard to the greenhouse for an illustrative purpose, the present invention is not limited to the greenhouse. For example, the present invention can be applied to structures including a cattle shed, such as a cow, domestic fowl or pig shed, and a commodity storage house that need ventilation.

Industrial Applicability

As described above, in accordance with the present invention, the greenhouse can withstand a heavy wind when the panes ofthe greenhouse are opened, the opening ratio ofthe greenhouse is increased, and the inflow and outflow of indoor and outdoor air can be smoothly and rapidly performed via the panes, thereby being capable of keeping the indoor temperature of the greenhouse appropriate to the growth requirements of agricultural products by natural ventilation without cooling means.

In addition, the greenhouse is unitized, so the greenhouse can be easily constructed and moved, and facilitates its maintenance due to the easy replacement of damaged panels. Additionally, each of the panels constituting the greenhouse is provided with an air layer between its upper and lower covers, so the greenhouse has superior insulation performance, thereby being advantageous to the maintenance of the appropriate indoor temperature ofthe greenhouse.

Accordingly, in accordance with the present invention, the ventilation, insulation and strength of the greenhouse are considerably improved and an decrease in cultivation costs is achieved. Additionally, when a structure, such as a cattle shed or factory, etc. is constructed of panels, superior ventilation can be achieved.

Claims

1. A panel for a greenhouse, comprising: an inner frame(20) provided with a plurality of engaging slits(26) at appropriate intervals on its inner surface, a fixing slit(27) in its longitudinal direction on its outer surface, and an opening(25) in its center; a plurality of cross-shaped bars(30) arranged in the form of lattices in the opening(25) of the inner frame(20) with both ends thereof inserted into the engaging slits(26); two covers(40) attached to upper and lower surfaces ofthe inner frame(20) to seal the opening; and an outer frame(50) provided in its inner portion with an engaging channel(51) and engaged with the inner frame(20) to cover the peripheral edges ofthe covers(40).

2. The panel for a greenhouse according to claim 1, wherein said covers(40) are made of one or more soft transparent sheets and are inserted into the fixing slit(27) ofthe inner frame by a wedge bar(43).

3. The panel for a greenhouse according to claim 2, wherein said covers(40) are formed in the shape ofa sealed barrel to receive the inner frame(20).

4. The panel for a greenhouse according to claim 2 or 3, further comprising two elastic plates(28), said elastic plates being inwardly formed along the edges ofthe fixing slit(27) to be elastically brought into contact with the wedge bar(43).

5. The panel for a greenhouse according to claim 1, wherein said cover(40) is made of a glass plate(42), and the peripheral edges of the glass cover is interposed between the inner and outer frames(20,50) and fixedly attached to the frames by a bonding agent.

6. The panel for a greenhouse according to claim 1, wherein said cross- shaped bar has a cross-shaped section, at least one rib(31,32) is formed to be larger than each of the other ribs(33,34) by a thickness of each rib, and a relatively long rib(31) and two neighboring ribs(32,34) are provided with a plurality of engaging slits(35,36,37) at regular intervals.

7. The panel for a greenhouse according to claim 1, further comprising a rainwater intercepting barriers(53), said rainwater barriers being formed on both side ends of an upper surface of said outer frame(50), respectively.

8. A panel for a greenhouse, comprising: an inner frame(20) provided with a plurality of engaging slits(26) with appropriate intervals on its inner surface, a fixing slit(27) in its longitudinal direction on its outer surface, and an opening(25) in its center; a plurality of cross-shaped bars(30) arranged in the form of lattices in the opening(25) of the inner frame(20) with both ends thereof inserted into the engaging slits(26); two covers(40) attached to upper and lower surfaces ofthe inner frame(20) to seal the opening(25); at least two body halves(61,62) each provided with an outer frame(50) provided with an engaging channel(51) and engaged with the inner frame(20) to cover the peripheral edges ofthe covers(40); and a folding means(63) by which said two body halves are pivotably connected to each other.

9. The panel for a greenhouse according to claim 8, further comprising two pairs of cover flanges(65,66) on the side ends of the body halves(61,62) to cover the peripheral edges of the upper surfaces of neighboring panels, and an additional cover flange(68) formed on one body half(61) to cover the upper end of another body half(62).

10. The panel for a greenhouse according to claim 9, further comprising an airtight packing(67) made of rubber and formed on the lower surface of each of the cover flanges(65,66).

11. A ventilation system for a greenhouse, comprising: one or more foldable panels(60) each consisting of at least two body halves(61,62) which are connected to each other by a folding means(63) for pivotal movement of said one body half(62); one or more guides(77) attached to at least one edge of said another body half(61); one or more panes for each foldable panel(60) having one or more guide rails(73) attached thereto and combined with said guide(77) for guiding the folding movement thereof; drive means for opening or closing said panes by moving one of body halves(61 or 62) of said foldable panels(60) with another body half(61 or 62) being pushed or pulled, resulting in pivotal movement of said body halves on said folding means(63).

12. The ventilation system for a greenhouse according to claim 11, wherein said drive means comprises a rotating shaft(81) provided with a pinion(82), a rack(84) engaged with the pinion(82), a guiding holder, a guiding holder rotatably fitted around the rotating shaft(81) for maintaining the engagement of the rack(84) and the pinion(82) and guiding the rack(84) during its movement, and a motor(88) for normal and reverse rotating ofthe rotating shaft(81).

13. The ventilation system for a greenhouse according to claim 12, wherein said rotating shaft(81) extends over said panels(60) provided with a pinion(82) and a rack(84) at regular intervals and operated by a single motor(88) at the same time.

14. The ventilation system for a greenhouse according to claim 11, wherein each of said guide rails(73) comprises two rail pipes arranged in parallel with each other to form a rail slit(76) therebetween and a holding bend(75a) is formed on one end portion of either ofthe two rail pipes.

15. The ventilation system for a greenhouse according to claim 11 or 14, wherein each of said guides comprises a bracket(79) attached to the upper edge of the body half(61) and a guide pin(80) rotatably attached with its one end to the bracket(79) and inserted with its other end into the rail slit(76) ofthe guide rail.

16. The ventilation system for a greenhouse according to claim 11, wherein each ofthe body halves(61,62) of said foldable panels(60) comprises: an inner frame(20) provided with a plurality of engaging slits(26) on its inner surface with appropriate intervals, a fixing slit(27) on its outer surface in its longitudinal direction, and an opening(25) in its center; a plurality of cross-shaped bars(30) arranged in the form of lattices in the opening(25) of the inner frame(20) and inserted with their ends into the engaging slits(26); two covers(40) attached to upper and lower surfaces ofthe inner frame(20) to seal the opening; and an outer frame(50) provided in its inner portion with an engaging channel(51) and engaged with the inner frame(20) to cover the peripheral edges ofthe covers(40).

17. The ventilation system for a greenhouse according to claim 16, wherein said covers(40) are made of soft transparent vinyl(41) or a glass plate(42).

18. The ventilation system for a greenhouse according to claim 11, wherein said foldable panels(60) are alternately arranged with fixed panels(lθ) in the walls of the greenhouse.

19. The ventilation system for a greenhouse according to claim 18, wherein said fixed and foldable panels(10,60) are equal in width.

20. The ventilation system for a greenhouse according to claim 18, wherein said foldable panels(60) are greater in width than said fixed panels.

21. The ventilation system for a greenhouse according to claim 18, 19 or 20, each of said body halves(61,62) comprise a cover flange(65 or 66) on either side thereof to cover the corresponding side of the neighboring fixed panel(s) and one of said body halves(61) is formed with an additional cover flange on a side opposing another body half(62) to cover the corresponding side thereof.

22. The ventilation system for a greenhouse according to claim 21, wherein an airtight packing(67) made of rubber is provided on the lower surface of each of the cover flanges(65,66) and a rainwater intercepting barrier(53) is provided on both side ends of said outer frame(50).

23. The ventilation system for a greenhouse according to claim 11, wherein said drive means is a hydraulic or pneumatic actuator.