JPS6013358Y2 - Covering sheet for tunnel house - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a covering sheet for a tunnel house, and more particularly to a covering sheet for a tunnel house used to promote the protection and growth of agricultural crops.

Conventionally, in order to promote the protection and growth of agricultural crops, it has been widely practiced to cover crop rows with transparent synthetic resin films or sheets in the form of tunnels.

By the way, since the synthetic resin films or sheets mentioned above generally do not have breathability, the temperature inside the tunnel house increases significantly during the day due to sunlight, and in some cases, the temperature rises above the optimum temperature for growing crops. , which inhibits crop growth, deteriorating yields and varieties, and in extreme cases can even cause crops to wither.

Therefore, if the daytime temperature rises, remove the synthetic resin film or sheet that forms the tunnel house, or cover the tunnel house with a cover to prevent sunlight, and re-cover or remove the cover at night. It is usually done.

However, the above work must be carried out in accordance with the weather conditions at the time.

It has the disadvantage that it is extremely complicated.

On the other hand, in order to eliminate such drawbacks, a large number of ventilation holes are bored in the film or sheet forming the tunnel house.
A device configured to prevent a rise in temperature during the day has been proposed, but it has the drawback that the temperature drops significantly during the night, making it difficult to set a stable temperature condition throughout the day and night.

In view of the above-mentioned drawbacks, this invention was made as a result of intensive research with the aim of obtaining a covering sheet for a tunnel house that can maintain good temperature conditions inside the tunnel house throughout the day and night. , and hole row portions are arranged and formed at positions near the center line in the width direction and sandwiching the center line, and the opening area of each hole forming the two hole row portions is 1rIr! A to 700rIrIA, and the total opening area of these holes is 0.5 to 3% of the surface area of the main body.

In this case, no restrictions are placed on the shape of the holes in the hole row section.

Next, this invention will be explained using examples.

FIG. 1 is a plan view of an embodiment of this invention, and FIG. 2 is a conceptual diagram showing how the embodiment is used.

The covering sheet A for a tunnel house of this invention is a belt-shaped transparent sheet 1 made of synthetic resin such as polyethylene, ethylene vinyl acetate, or polyvinyl chloride.
Hole array portions 2A and 2B are arranged and formed at positions sandwiching the center line IB, near the longitudinal side edge IA and the center line IB in the width direction (arrow X), respectively. The opening area of each hole 2 forming the two hole rows 2A and 2B is ITIr! t~700TIr1ft, and the total opening area of these holes 2 is 0.5~3% of the surface area of the main body 1.

Note that although the hole row portions 2A and 2B are shown as negative rows, one hole row portion may have two or three hole rows as long as the above numerical range is also satisfied.

The tunnel house covering sheet A of this invention is
As shown in FIG. 2, a pillar (not shown) erected in an arch over the crop B is covered with the center line IB aligned with the top of the arch to form a tunnel house A'.

At this time, the tunnel house A' has two hole rows 2A.
, 2B are formed at asymmetric positions, one of which is formed below the side of the tunnel house A', and the other near the top of the tunnel house A'.

Therefore, in this tunnel house A', when the daytime temperature rises, the warmed air inside the tunnel house' is discharged from the hole row section 2B that opens near the top, and at the same time, the outside air flows downward from the side. The air is taken in through the hole row section 2A, suppressing the rise in temperature inside the greenhouse, while at night, as is clear from the test results described later, an inversion layer of temperature is created inside the greenhouse due to the two asymmetrically placed ventilation holes. This is because there is no significant drop in temperature.

Also, the opening area of each hole in the hole row section is l-~7
00-1 and the total area of the openings is 0 of the total area of the sheet
．． The reason for limiting the opening area to 5 to 3% is that if the opening area is less than 0.5% of the total area of the sheet, sufficient ventilation cannot be achieved, and if it is more than 3%, ventilation becomes too good.
This is because the temperature decreases significantly at night, and the opening area of each hole 2 is within the above-mentioned opening ratio and determines the density of the holes, and if the hole area is less than 1- If sufficient ventilation is not achieved, and if the area of the hole becomes large, the amount of ventilation from each hole will increase, but the opening will become too rough and cause uneven temperature inside the house, so the maximum limit should be 700 TrIit or less. This is desirable.

In addition, in the above range, the opening area of the hole is 78d~3
Most preferably, the diameter is 14 m and the aperture ratio is 2%.

Next, experimental results will be shown when a tunnel house was formed using the covering sheet A of this invention.

Experiment 1 A tunnel house was constructed as shown in Figure 3.The temperature changes inside the tunnel house during the day and night were measured.

Figure 3 A shows one made of vinyl film with no ventilation holes at all, Figure 3 shows one with ventilation holes provided at symmetrical positions around the circumference of the tunnel, and Figure 3 C shows one made of vinyl film with no ventilation holes at all. The one with ventilation holes only in a few places, and the one in Figure 3-2 is one in which both ends of the tunnel are rolled up, allowing ventilation only during the day.

The state of temperature change was as shown in FIG. 4.

Note that the middle part of the figure shows changes in outside temperature.

According to the results, it was found that in the case of the covering sheet A of the present invention, while there was no significant increase in temperature during the day, it was also possible to prevent a decrease in temperature at night.

In addition, the change in soil temperature inside the tunnel was as shown in Figure 5, and good results were obtained with little change in soil temperature.

Since this invention is constructed as described above, when a tunnel house is formed, temperature changes during the day and night are alleviated by the ventilation holes formed at asymmetric positions, and therefore,
This makes it possible to leave the tunnel house without tension, which greatly reduces labor.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of this invention, Fig. 2 is a conceptual diagram showing the usage state of the embodiment, Fig. 3 A to Fig. 2 are explanatory diagrams showing a comparative example, and Figs. 4 and 5. is a graph showing the test results. A...Covering sheet for tunnel house, 1...
...Sheet, IA...Longitudinal side edge, 1B
... Center line in punching direction, 2 ... Hole, 2A, 2B.
...hole row section.

Claims (1)

[Scope of utility model registration request] Near the edge in the longitudinal direction and near the center line in the width direction,
Hole array portions are arranged and formed at positions sandwiching the center line, respectively,
The opening area of each hole forming the above two hole rows is 1rdt to 700rrd, and the total opening area of these holes is 0.5 to 3% of the surface area of the main body.
A covering sheet for a tunnel house, characterized in that it is configured as follows.