JPH0638727B2 - Pressing member for greenhouse sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a greenhouse sheet pressing member for pressing a sheet used for a roof of a greenhouse and fixing the sheet to a sheet receiving member.

[0002]

2. Description of the Related Art Generally, a sheet made of, for example, a polyester resin film is laid on a sheet receiving member such as rafters which constitutes a roof frame of a greenhouse, and the sheet is pressed onto the sheet receiving member and fixed by using a sheet pressing member. And constitutes the greenhouse.

[0003]

However, when a sheet made of the polyester resin film is used, this sheet does not transmit ultraviolet rays, so natural sunlight of the sun does not enter the greenhouse, so that the color of the eggplant is deteriorated. Or, there was a problem that strawberries are difficult to be pollinated because the bees do not fly, and also, since the sheet made of the polyester resin film is relatively poor in weather resistance, it is necessary to refill it, Although used sheets will be discarded, there was a problem that harmful gas was generated during incineration.

By the way, the natural rays of the sun are sufficiently transmitted, and
Since a weather-resistant fluororesin film has been developed, it is possible to solve the above problems by using a sheet made of this fluororesin film, but a sheet made of a fluororesin film has a large thermal expansion, Therefore, when the sheet is stretched in the summer, there are few problems, but when stretched in the winter when the temperature is low, the temperature rises in the summer and the sheet thermally expands, causing wrinkles and slack in the sheet, resulting in an appearance. Not only worsen, but also fluttering due to wind causes noise and weakens the strength of the film, and if the nighttime temperature drops during the interim period, condensation will collect on these wrinkles and water drops will fall on the crops. It turned out to be a problem.

The present invention focuses on a pressing member used for tensioning the sheet, and when the sheet is tensioned using the pressing member, the sheet tensioning condition and the expected temperature rise during use are taken into consideration. In addition, it is possible to give the above-mentioned elongation to the sheet with respect to the elongation due to the thermal expansion corresponding to the operating temperature range, so that the problem of the sheet tension due to the thermal expansion can be solved. While using a sheet made of a fluorine-based resin film that allows sufficient sunlight to pass through and has good weather resistance, it is possible to prevent wrinkles and sagging from occurring even when the temperature rises in the operating temperature range. The point is to provide a pressing member that can be used.

[0006]

To achieve the above object, in the present invention, a sheet 5 made of a fluorine resin film is pressed onto a sheet receiving member 4 in a greenhouse, and the sheet 5 is placed on the sheet receiving member 4. A pressing member for a greenhouse sheet to be fixed to the sheet receiving member, which is wider than the sheet receiving surface of the sheet receiving member 4, and which holds the sheet 5 on the sheet receiving member 4; And a pressing leg portion 9 that extends in the length direction of 8 and presses the sheet 5 when the sheet 5 is clamped, and the protrusion height of the pressing leg portion 9 with respect to the clamping portion 8 is The height is set so as to give the sheet 5 an elongation of 0.7% or more when the sheet 5 is sandwiched.

Further, the protrusion height of the pressing leg portion 9 is set to the sheet 5
When sandwiched between the sheet receiving member 4 and the sheet receiving member 4, it is preferable that the sheet 5 has a height that gives an expansion rate of about 3 to 4 times the actual expansion coefficient of the sheet 5 at a temperature difference of 10 ° C to 42 ° C. .

[0008]

[Function] When cultivated in a greenhouse, it is usually heated in the winter, and therefore generally does not fall below 10 ° C. Also, even if it is ventilated in the summer, if it is not air-conditioned Since the temperature is higher than the outside temperature, the operating temperature range of the sheet 5 is usually 10 ° C to 42 ° C. Therefore, this greenhouse temperature range, that is, 10 to 4
When the expansion coefficient at 2 ° C. is examined, the expansion coefficient of the fluorine-based resin film varies depending on the composition and manufacturer, but the minimum expansion coefficient is 0.23%. Therefore, using the film having a coefficient of expansion of 0.23% as the sheet 5,
When the sheet 5 is stretched on the sheet receiving member 4,
That is, when the sheet 5 is sandwiched by the sandwiching portion 8 while the sheet 5 is being pressed by the pressing leg portion 9, theoretically, the sheet 5 may be stretched at an elongation rate slightly larger than 0.23%. However, after conducting various tests, for example, tensioning work was performed at 10 ° C and the greenhouse temperature was 42 ° C.
When the sheet is lifted up, many wrinkles were formed on the stretched sheet in the direction orthogonal to the length direction of the sheet receiving member.

This is because, when the sheet is stretched, the elongated sheet is used, and the sheet receiving member interval is, for example,
While the length is 60 cm, the length of the sheet receiving member is 5
This is because the sheet restraining force of the sheet with respect to the stretched length is very small even if the sheet is fixed on both sides in the length direction of the sheet receiving member.

Therefore, as a result of various tests assuming generally a stretched state, it is necessary to give an elongation rate of 0.7% or more to the film having a coefficient of expansion of 0.23% when stretched. After confirming that there is a sheet, the sheet receiving member 4
The pressing leg portion 9 is provided on the pressing member to be pressed to
The height of the pressing leg portion 9 is set to a height that allows the elongation rate of 0.7% or more of the sheet.

However, by constructing the pressing leg portion 9 as described above, when the sheet 5 is stretched, it is possible to give the sheet 5 an elongation rate of 0.7% or more. Even when the seat 5 is stretched in the winter, even if the temperature of the seat 5 rises due to the rise in the summer air temperature and the seat 5 expands due to thermal expansion, this expansion is caused when the seat 5 is stretched. 0.7% given to sheet 5
It can be absorbed by the above elongation, and the sheet 5 does not have wrinkles.

Therefore, the sheet 5 made of a fluorine-based resin film having sufficient weatherability of the sun and good weatherability.
To grow crops in the same way as open field cultivation,
While reducing waste pollution, preventing wrinkles and slack from occurring in the seat 5 when the temperature rises, not only making the appearance worse due to wrinkles, but also making noise and film strength due to flapping by wind. It is possible to prevent the damage to the crops due to the fall of the dew condensation even if the temperature drops in the middle period. The elastic limit rate of the film is 5 to 6%, and it is preferable that the height of the pressing member 9 be high within the elastic limit range, but it is not necessary to give an unnecessary elongation rate. Also, the higher the elongation to be applied, the worse the workability at the time of tensioning, so it is preferable to set it to about 1.7% or less at most.

Further, the protruding height of the pressing leg portion 9 is set to the sheet 5
When the sheet 5 is sandwiched between the sheet receiving members 4 and the sheet 5 has a height that gives an expansion rate of about 3 to 4 times the actual expansion coefficient of the sheet 5 at a temperature difference of 10 ° C. to 42 ° C.,
Even when the sheet 5 made of a film having a different composition and a different expansion coefficient is used, the sheet 5 made of these films can be stretched by giving an appropriate elongation and can be used without deteriorating the workability of stretching. Wrinkles can be prevented from occurring even in a high temperature region in the temperature range, and the tensioned state can be maintained.

[0014]

EXAMPLE A roof of a greenhouse schematically shown in FIG. 4 has a gas stove 2 diagonally arranged from an upper end of a true bundle 1 to an eaves (not shown),
A plurality of haze materials 3 are arranged in parallel with each other on the gassho 2 at a predetermined interval, and on the haze material 3,
A rafter 4 extending orthogonally to the haze 3 is provided, and the rafter 4
As a sheet receiving member, a sheet 5 made of a fluorine-based resin film is pressed onto the rafter 4 by a sheet pressing member 6 to be described later, and is fixed to the rafter 4.

As shown in FIG. 1, the rafters 4 arranged on the haze material 3 are formed by bending a metal plate material to form a sheet receiving member. 3, a pair of bending walls 42, 43 bent upward from both ends in the width direction of the solid wall 41, and the bending wall 42,
The upper end of 43 is provided with receiving portions 44 and 45 for receiving the sheet pressing member 6 formed on the rectangular tube in cross section, and the sheet pressing member 6 is provided between these receiving portions 44 and 45.
A space that is slightly narrower than the screw diameter of the screw 7 that fastens the sheet is provided, and the sheet pressing member 6 is fixed on the rafter 4 by screwing the screw 7 between the spaces.

Further, as shown in FIG. 1, the sheet pressing member 6 receives the sheet 5 by the both receiving portions 44, 4.
5 and a pair of pressing legs 9 extending obliquely downward from both ends of the sandwiching portion 8 in the width direction, and the screw is provided at the center of the sandwiching portion 8 in the width direction. 7 is formed, and the width of the sandwiching portion 8 is formed wider than the width of the sheet receiving surface composed of the both receiving portions 44 and 45. ,
The pair of pressing legs 9 are extended in the lengthwise direction of the sandwiching portion 8, and the projecting height of the pressing legs 9 with respect to the sandwiching portion 8 is such that when the sheet 5 is sandwiched, 0.7% to 5
This is the height that gives the above elongation. Reference numeral 61 is a reinforcing flange for reinforcing the sheet pressing member 6.

By the way, when a plant is generally grown in a greenhouse, it is usually heated in the winter, so that the temperature generally does not fall below 10 ° C., and even if it is ventilated in the summer. Since the internal temperature is higher than the outside temperature,
The operating temperature range of the greenhouse is usually 10 to 42 ° C.
Therefore, when the coefficient of thermal expansion of the fluorine-based resin film in this temperature range was examined, it was found that, for example, with the product name TOYOFLON (a thickness of 60 microns manufactured by Toray Industries, Inc.), the minimum coefficient of expansion was 0.23%. understood. Therefore, when the film is used as the sheet 5, it is assumed that when the sheet 5 is stretched, it is possible to absorb thermal expansion by giving the sheet 5 an elongation slightly larger than 0.23%.
An interval (usually 60) shorter than its length (eg 5-6 m)
cm) and is stretched between the rafters 4, and even if both ends in the length direction are fixed, the elongation in the direction parallel to the rafters 4 is larger than that in the orthogonal direction. Since it is difficult to be restrained, it was confirmed that wrinkles were generated even when the sheet 5 was stretched by 0.23% as described above. Therefore, the sheet 5 is stretched between the rafters 4 arranged in parallel at intervals of 60 cm, and the pressing leg portion 9 presses the sheet 5 downward to change the elongation given to the sheet 5 to cause wrinkles. When observed, 0.7
It has been found that the sheet 5 does not have wrinkles or sagging when an elongation of 0.1%, that is, an elongation of about 3 times 0.23% is applied.

Further, FIG. 2 shows the product name FCLEAN 6 which is made of a fluorine resin film having a composition different from that of TOYOFLON.
The result of the actual measurement of the change in the coefficient of thermal expansion with respect to the temperature of 0 (manufactured by Nippon Carbide Industry Co., Ltd., thickness of 60 microns) is shown. Can be considered to change approximately linearly, and the expansion coefficient at 10 ° C and 4
By comparing the difference in expansion coefficient at 2 ° C., it can be seen that the difference in expansion coefficient due to the temperature difference of 10 to 42 ° C. is 0.43%. Therefore, F-Clean 60 is used for the sheet 5
As in the case of Toyofuron, parallel to 60
The sheet 5 is stretched at 30 ° C. between rafters 4 having a length of 200 cm and arranged at intervals of cm, and the elongation given to the sheet 5 is changed, and the difference in expansion coefficient of the sheet 5 from 10 to 42 ° C. is 0. It was observed that wrinkles were generated by raising the temperature to 55 ° C., which is a temperature difference corresponding to 0.43%, and gave a stretch of about 4 times the actual expansion coefficient value of F-Clean 60 at the temperature difference of 10 to 42 ° C. It was found that wrinkles did not occur on the sheet 5 at that time. Therefore, as a result of observing on the high temperature side where the coefficient of thermal expansion is large as compared with the temperature range of 10 to 42 ° C, about 4 times was obtained, so wrinkles could not be formed at about 3 times in the temperature range of 10 to 42 ° C. It can be predicted that the temperature range of the greenhouse used is 10 to 42 ° C.
It has been found that wrinkles can be prevented by increasing the elongation given to the sheet 5 to about 3 to 4 times the actual expansion coefficient in the operating temperature range of the film used for the sheet 5, that is, the temperature range of 10 to 42 ° C. Of.

Further, as can be seen from FIG. 2, 10 to 42
Since the coefficient of thermal expansion is higher on the high temperature side in the temperature range of ° C, when the FCLEAN 60, which is made of a fluorine-based resin film having a composition different from that of TOYOFLON, is used as the sheet 5, the pressing leg 9 is projected. Seat height 5
When sandwiched between the rafters 4, the sheet 5 has an elongation rate of about 3 to 4 times the measured expansion rate value of the sheet 5 at a temperature difference of 10 to 42 ° C., that is, 1.29 to 1.72%. The height that gives the elongation, that is, 0.9 in the embodiment shown in FIG.
It is cm.

Next, using the sheet 5 made of the F-clean 60, the protrusion height H of the pressing leg portion 9 is 0.9 cm on the rafter 4 having a length of 5.5 m.
A procedure for stretching the sheet pressing member 6 will be described.

That is, as shown in FIG. 3, of the three rafters 4, the double-sided tape T is attached to both the receiving portions 44 and 45 of the rafters 4 arranged on both sides, and about 13 pieces of the tape are attached thereon.
The sheet 5 wound into a roll having a width of 0 cm is shown in FIG.
Is laid from the ridge side to the eaves side, and both widthwise ends of the sheet 5 are attached and fixed on each rafter 4 via the double-sided tape T.

Further, the sheet pressing member 6 is attached to each rafter 4
By arranging them so as to overlap with each other and pressing each sheet pressing member 6 downward, the pressing leg portion 9 moves the sheet 5 downward until the sandwiching portion 8 abuts on both the receiving portions 44 and 45. By pressing and fixing the sandwiching portion 8 to the rafter 4 by the screw 7, the sheet 5 is fixed to the sandwiching portion 8
While sandwiching between the two receiving portions 44 and 45,
The sheet 5 between the rafters 4 is stretched by the pressing legs 9. In this case, the height of the pressing leg portion 9 is set to 0.9 cm, and the pressing leg portion 9 is provided at a wider width than the sheet receiving surface composed of the receiving portions 44 and 45. In contrast, the elongation to be applied is 0.97 cm, and the elongation is 1.61% with respect to the 60 cm spacing of the rafters 4, and the measured expansion coefficient value 0.43 shown in FIG. 3.7%
It doubles.

As described above, when the sheet 5 is sandwiched by the sandwiching portion 8 while the sheet 5 is being pressed by the pressing leg portion 9, the sheet 5 should have an elongation of 1.61%. Therefore, for example, the difference in expansion coefficient in the greenhouse temperature range, that is, 10 to 42 ° C. is 0.
When a 43% fluorine-based resin film (F-CLEAN 60) is used as the sheet 5, and when the sheet 5 is stretched on the rafter 4, the sheet 5 is stretched in the winter,
Even if the temperature of the sheet 5 rises from 10 ° C. to 42 ° C. due to the rise in summer temperature and the sheet 5 expands due to thermal expansion, this expansion is 1.61% given to the sheet 5 when stretched. The sheet 5 can be absorbed and the sheet 5 does not have wrinkles or sagging.

Therefore, the sheet 5 made of a fluorine-based resin film having sufficient weatherability of the sun and good weatherability.
To grow crops in the same way as open field cultivation,
While reducing waste pollution, it prevents wrinkles and slack from occurring on the sheet 5 when the temperature rises, and wrinkles cause the appearance to deteriorate, as well as produce noise due to wind fluttering and weaken the strength of the film. Can be prevented, and
Even if the temperature drops during the interim period, it is possible to prevent damage to crops due to the fall of dew condensation.

As described above, the protrusion height of the pressing leg portion 9 is set so that the sheet 5 is sandwiched between the rafter 4 and the sheet 5.
At a height that gives an expansion rate of about 3 to 4 times the actual expansion rate of the sheet 5 at a temperature difference of 10 ° C. to 42 ° C., that is, the film having an expansion rate of 0.43%, for example. When used, when the rafters 4 are arranged at intervals of 60 cm, the rafters 4 are set to 0.97 cm so that the sheet 5
Even when the sheet is stretched, the sheet can be stretched by giving an appropriate elongation according to the sheet 5, and wrinkles can be prevented from occurring even in a high temperature region in the operating temperature range without deteriorating the workability, and the stretched state can be maintained. It can be maintained.

When a large number of irregularities are formed on each of the reinforcing portions 61 provided at both ends of the sandwiching portion 8 in the width direction, it can be used as a slip stopper when the sheet 5 is stretched,
The tensioning work can be performed safely.

[0027]

As described above, according to the present invention, a sheet for a greenhouse in which a sheet 5 made of a fluorine resin film is pressed onto the sheet receiving member 4 in a greenhouse and the sheet 5 is fixed on the sheet receiving member 4. A pressing member having a width wider than the sheet receiving surface of the sheet receiving member 4, and a sandwiching portion 8 for sandwiching the sheet 5 on the sheet receiving member 4, and a longitudinal direction of the sandwiching portion 8. It is composed of a pressing leg portion 9 that extends and presses the sheet 5 when the sheet 5 is clamped. The protrusion height of the pressing leg portion 9 with respect to the clamping portion 8 is set when the sheet 5 is clamped. Since the height of the sheet 5 is set to give the elongation rate of 0.7% or more, the sheet 5 is attached to the pressing leg 9
When the sheet 5 is sandwiched by the sandwiching portion 8 while being pressed by the sheet, it is possible to give the sheet 5 an elongation rate equal to or more than the difference in the expansion rate in the usage range of the greenhouse, and thus a fluorine-based material having a high expansion rate is used. When the sheet 5 made of the film is stretched in the winter in a greenhouse in which the length of the sheet receiving member is longer than the distance between the sheet receiving members while using the resin film, the temperature of the sheet 5 rises due to an increase in summer air temperature. Even if the sheet 5 expands due to thermal expansion, the elongation can be absorbed by the elongation of 0.7% or more that can be given to the sheet 5 when the sheet 5 is stretched. No wrinkles occur in No. 5.

Therefore, the sheet 5 made of a fluorine-based resin film, which has sufficient weatherability and allows natural sunlight to pass therethrough.
To grow crops in the same way as open field cultivation,
While reducing waste pollution, it prevents wrinkles from occurring on the sheet 5 when the temperature rises, preventing the appearance from being wrinkled, and also preventing noise and weakening of the film strength due to flapping by the wind. Even if the temperature drops in the middle period, it is possible to prevent damage to crops due to the fall of dew condensation.

Further, the protrusion height of the pressing leg portion 9 is set to the sheet 5
When the sheet 5 is sandwiched between the sheet receiving member 4 and the sheet 5, the height of the sheet 5 is about 3 to 4 times the expansion rate of the sheet 5 at the temperature difference of 10 ° C to 42 ° C. Even when the sheet 5 made of a film having a different composition and a different expansion coefficient is used, the sheet 5 made of these films can be stretched by giving an appropriate elongation and can be stretched in a working temperature range without impairing workability. Wrinkles can be prevented from occurring even in a high temperature region, and the tensioned state can be maintained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of the present invention.

FIG. 2 is a graph showing the actual measurement results of the coefficient of thermal expansion of a fluorine-based resin film.

FIG. 3 is a schematic cross-sectional view showing a state when the seat is stretched.

FIG. 4 is a partial cross section of a greenhouse roof.

[Explanation of symbols]

 4 Seat receiving member (rafter) 5 Seat 8 Clamping part 9 Pressing leg

Claims (2)

[Claims] 1. A pressing member for a greenhouse sheet, comprising: pressing a sheet 5 made of a fluororesin film onto a sheet receiving member 4 in a greenhouse and fixing the sheet 5 on the sheet receiving member 4; A sandwiching portion 8 that is wider than the sheet receiving surface of the member 4 and sandwiches the sheet 5 on the sheet receiving member 4, and a sandwiching portion of the sheet 5 that extends in the length direction of the sandwiching portion 8. When the sheet 5 is clamped, the protrusion height of the pressing leg 9 is 0.7% or more when the sheet 5 is clamped. A pressing member for a greenhouse sheet, which is characterized in that it has a height that gives the elongation rate of. 2. A greenhouse sheet pressing member for pressing a sheet 5 made of a fluorine-based resin film onto a sheet receiving member 4 in a greenhouse and fixing the sheet 5 on the sheet receiving member 4. A sandwiching portion 8 that is wider than the sheet receiving surface of the member 4 and sandwiches the sheet 5 on the sheet receiving member 4, and a sandwiching portion of the sheet 5 that extends in the length direction of the sandwiching portion 8. When the sheet 5 is clamped to the sheet receiving member 4, the protrusion height of the pressing leg 9 with respect to the sandwiching portion 8 is set to the sheet 5 when the sheet 5 is sandwiched. 2. A pressing member for a greenhouse sheet, which has a height that provides an expansion rate of about 3 to 4 times the actual expansion coefficient of the sheet 5 at a temperature difference of 10 ° C. to 42 ° C.