JP2000064623A - Air tent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of an air tent and to make a retaining net usable for sheets of various sizes by using polyethylene sheet for the air tent, and cutting out four corners of the keep net to form cross shape. SOLUTION: An air tent A temporarily installed with its peripheral edge part fastened to a pool side 1a to cure concrete placed at a swimming pool has a retaining net N put over a sheet S to restrain the sheet S from being excessively expanded by internal pressure. This sheet S is formed by heat- welding a polyethylene film to one face of fabric with polyethylene yarn alternately woven so as to reduce weight to about one - tenth of a conventional vinyl chloride resin sheet and cutting a body part and both end gable parts of circular arc shape three-dimensionally. The retaining net N is formed of polyethylene twist yarn into rectangular mesh and omitted parts 10 are provided at four corners to form cross shape on the whole without three-dimensional cutting. The weight of the sheet S is therefore reduced, and the retaining net N is usable for the sheets S of various sizes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air tent which is provided above a concrete such as a pool or a rooftop to protect the concrete from rainwater when the concrete is cured.

[0002]

2. Description of the Related Art An air tent may be provided above a concrete pouring surface for outdoor use such as a pool or rooftop. By doing so, the concrete placing surface is protected from rainwater and the like. In this air tent, the peripheral edge of the sheet obtained by three-dimensionally cutting a vinyl chloride resin into a predetermined shape is installed on the periphery of the concrete placing surface,
The internal pressure is increased by blowing air inside the sheet with a blower. By doing so, the sheet is expanded into a dome shape. Then, in order to prevent the sheet from being excessively expanded, a holding net may be attached to almost the entire outside of the sheet.

For example, when an air tent is installed for curing a pool of 25 m × 15 m (see FIG. 2), a sheet of about 28 m × 19 m is required.
The sheet constituting the conventional air tent is made of vinyl chloride resin, and the weight of this sheet is about 600 kg. For this reason, it is extremely difficult to carry and set the sheet only manually, and a large heavy machine is required. In particular, when this air tent is temporary, it is frequently attached and detached, and a heavy machine is required each time. Further, the surface of the sheet has a smooth surface. Therefore, when the sheet is folded and stored, the sheet surfaces are firmly adhered to each other by rainwater or the like, and a lot of manpower is required to extend the sheet during installation.

Further, when a presser net is used in a conventional air tent, and when the seat is provided with an entrance / exit, the part of the presser net corresponding to the entrance / exit must be omitted. Therefore, the strength of the presser net may be reduced. Further, since the pressing net presses almost the entire area of the sheet, it is necessary to prepare many kinds of pressing nets according to the size of the sheet.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention makes it possible to share a holding net for sheets of different sizes and reduce the weight of the sheets, thereby installing an air tent. The challenge is to make it easy.

[0006]

According to the present invention for solving the above-mentioned problems, a sheet having a peripheral portion installed on the ground surface and expanded into a dome shape by a blower, and the sheet is pressed from the outside. In an air tent for protecting concrete under curing, which is provided above a concrete placing surface of a construction site with a holding net for suppressing excessive expansion of the sheet, in the holding net, It is characterized in that the four corners corresponding to the corners of the sheet are missing.

Air is blown into a sheet whose peripheral portion is located on the ground surface, and the sheet is expanded into a dome shape.
The presser net installed on the upper surface of the sheet presses the sheet as the sheet expands. The four corners of the presser net corresponding to the corners of the sheet are omitted in advance. Since the peripheral portion of the sheet is restrained by the ground surface, the degree of expansion of the sheet is not constant over the entire area. That is, the degree of expansion at the corner is smaller than the degree of expansion at the top of the seat. Then, when the sheet expands, the degree of expansion of the sheet becomes maximum in a portion substantially on the center line in the longitudinal direction of the sheet and a portion substantially on the center line in the width direction. Is small. As a result, even if a portion of the holding net corresponding to the corner portion of the sheet is missing, the portion does not expand excessively.

Further, when the sheet constituting the air tent is formed by alternately weaving yarns made of polyethylene, it is lighter in weight than the conventional vinyl chloride resin sheet. Moreover, since the polyethylene threads are alternately woven, fine irregularities are formed on the surface, so that the surfaces do not come into close contact with each other. As a result, the work of stretching the sheet is easy.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples. 1 is a perspective view of an air tent A according to the present invention, and FIG. 2 is a plan view showing a state in which a seat S and a holding net N constituting the air tent A are installed on a poolside 1a,
3 is a plan view showing a method of manufacturing the sheet S, FIG. 4 is a partially enlarged view of the sheet S, FIG. 5 is an enlarged sectional view taken along line XX of FIG. 4, and FIG. 6 is a perspective view of the doorway 8. In this specification, FIG. 1 and FIG.
, The length L ₁ is 25 m and the width W ₁ is 15 m.
The case where the air tent A for curing concrete cast in the pool 1 is temporarily installed on the pool side 1a will be described. First, the sheet S will be described. The size of this sheet S is larger than that of the pool 1, and the length L
₂ is about 28 m and the width W ₂ is about 19 m. And FIG.
As shown in FIG. 3 and FIG.
And arc-shaped gable portions 3 arranged at both ends in the longitudinal direction thereof, and both edge portions 2a in the longitudinal direction of the sheet body portion 2, and respective peripheral edge portions 3a of the gable portion 3. Are matched and three-dimensionally cut. Therefore, the sheet S is formed in a three-dimensional shape in which the sheet main body 2 is slightly raised.

As shown in FIGS. 4 and 5, this sheet S has thin polyethylene warp yarns 4a having a thickness of 1000 to 1500 denier and weft yarns 4b, which are alternately arranged at a rate of 10 to 18 per inch. It is formed by weaving. By alternately weaving the warp yarns 4a and the weft yarns 4b, minute irregularities are formed on the surface thereof. Then, a polyethylene film F having a thickness of 30 to 80 microns is heat-sealed on one surface thereof. By doing so, the sheet S is waterproofed.

Next, the weight of the sheet S will be calculated. The sheet S is provided with a polyethylene thread 4 having a thickness of 1000 denier.
Is woven 10 per inch, and a 30-micron polyethylene film F is fused on one side. One denier is 0.05 g / 450 m. The specific gravity of polyethylene is 0.95. 1 of 1000 denier polyethylene yarn (warp yarn 4a and weft yarn 4b)
The weight per m is 1000 × 0.05 / 450 = 0.1
It is 1 (g). Therefore, at 1 inch (25.4 mm), 0.11 × 25.4 × 10 ⁻³ = 2.8 × 10
^-3 (g).

Since ten warp threads 4a and ten weft threads 4b are woven in each of the longitudinal direction and the transverse direction, the weight per square inch is 2.8 × 10 ⁻³ × (10+
10) = 0.056 (g). The weight per square inch of the polyethylene film F fused on one side is 2.54 × 2.54 × 0.003 × 0.95 =
It is 0.018 (g). As a result, the weight per square inch of the sheet S is 0.056 + 0.018 = 0.0.
74 (g), length L ₂ is 28 m, width W ₂ is 19 m
Sheet S has a total weight of 28 × 10 ³ × 19 × 10 ³ ×
0.074 × 10 ⁻³ /(25.4×25.4)=61
(Kg). In the case of conventional vinyl chloride resin, the total weight of the sheets S of the same size is about 600 kg, so
Weight is reduced to 10.

At both ends in the longitudinal direction of the sheet S, as shown in FIG. 2, two blower pipes 5a, 5 are provided.
b is provided. The multi-blade blower 6 for pressurization is connected to the blower pipe 5a on one side, and the blower pipe 5 on the other side is connected.
A blower fan 7 for blowing air is connected to b. The multi-blade blower 6 is for keeping the internal pressure P (see FIG. 10) of the air tent A constant (static pressure 20 to 50 mm). The blower fan 7 connected to the blower pipe 5b on the other side is for blowing air into the seat S,
The air volume is 18 to 42 m ³ / min. When inflating the seat S to start up the air tent A, first, both the multi-blade blower 6 and the blower fan 7 described above are simultaneously operated. When the internal pressure P of the air tent A reaches a predetermined pressure, the blower fan 7 is stopped. Then, by operating only the multiblade blower 6, the internal pressure P of the air tent A is kept constant.

Further, as shown in FIGS. 2 and 6, entrances / exits 8 are provided in the vicinity of one diagonal corner C of the seat S. The inlet / outlet 8 is made of the polyethylene thread 4 described above, and is integrally provided on the side surface of the sheet S. An opening / closing port 8a made of a plastic fastener is provided on the outer side surface portion. A person can enter and leave the air tent A through the doorway 8. Fasteners are also provided on the seat S itself at the entrance / exit 8, and a double fastener structure is formed with the fasteners on the outer side surface, so that the internal pressure P of the air tent A decreases due to the entry and exit of a person. There is no.

Next, the presser net N will be described. As shown in FIG. 6, the presser net N has a thickness of 2.
It is obtained by knitting a polyethylene twisted yarn 9 of 4 to 3 mm into a square mesh having a length of 50 to 100 mm. Its weight is 46-80g per square meter, and its strength is 1000-1500 per square meter.
It is kg. As shown in FIG. 2, the presser net N of the present embodiment is formed in a substantially thick cross shape, with four corners being cut off to provide cutouts 10. Therefore, it is not necessary to perform steric cutting at the time of molding the presser net N, and the presser net N can be molded as it is in a planar shape, which is advantageous in that it can be easily molded. The presser net N has a maximum length L ₃ of 34 m and a maximum width W ₃ of 22 m.
And its total area is about 638 m ² . Assuming that the weight of the twisted yarn 9 is 46 g per square meter, the total weight of the presser net N is 638 × 46/1000 = 29.3 (k
g).

Next, the operation of installing the air tent A will be described. As shown in FIG. 7, on the pool side 1 a, along the outer peripheral edge of the pool 1, a single pipe 11
Is laid and fixed. The sheet S is installed so as to cover the entire concrete placing surface 1b of the pool 1, and the peripheral portion thereof is placed on the single pipe 11. As shown in FIGS. 8 and 9, the vicinity of the peripheral edge of the sheet S is double-folded to form an overlapping portion 12, and a large number of eyelets 13 are formed in this portion along the length direction of the sheet S. Are installed at regular intervals. The overlapping portion 12 of the sheet S is arranged almost directly above the single pipe 11. The tip end of the binding band 14 wound around the single pipe 11 is inserted through the eyelet 13 into the binding portion 14a provided at the end of the binding band 14 to prevent the binding band 14 from coming off. By doing so, the sheet S is fixed to the single pipe 11 in a close contact state.

The portion below (over the leading edge) the overlapping portion 12 of the sheet S is disposed inside the air tent A while contacting the single pipe 11, and the air leakage prevention portion 1 is provided.
5 is formed. The length of the air leakage prevention portion 15 is about 1 m from the overlapping portion 12. When the inside of the sheet S is pressurized by the multi-blade blower 6, its internal pressure P
Acts vertically on the inner surface of the sheet S. Similarly, since the internal pressure P acts vertically on the air leakage prevention unit 15,
The air leakage prevention portion 15 is pressed against the pool side 1a and is brought into close contact therewith. Therefore, the seat S and the poolside 1a
The airtightness with is maintained. The presser net N is placed on the upper surface of the sheet S thus installed. Then, as in the case of the sheet S, the peripheral portion of the holding net N is fixed to the single pipe 11 by the binding band 14.

Subsequently, the multi-blade blower 6 and the blower fan 7 blow air into the sheet S. The internal pressure P of the sheet S is gradually increased and expanded into a dome shape. As shown in FIG. 10, as the sheet S expands, the presser net N
Also gradually stretch. When the internal pressure P of the seat S reaches a predetermined pressure, the operation of the blower fan 7 is stopped, and only the multi-blade blower 6 operates. Therefore, the internal pressure P of the air tent A is kept substantially constant. The size of the presser net N corresponds to the size of the outer peripheral surface of the sheet S expanded to a predetermined pressure, and the presser net N presses the sheet S so that the sheet S expands excessively. Is suppressed.

Here, as shown in FIG. 11, the presser net N is provided with the cutout portions 10 at the portions corresponding to the respective corner portions C of the four corners of the sheet S, and has a substantially thick cross shape in plan view. ing. The peripheral portion of the sheet S is bound and bound to the single pipe 11 over the entire circumference. Therefore, the degree of expansion of the sheet S is smaller as it is closer to the peripheral edge portion, and conversely, the degree of freedom of the sheet S is larger as it is further away from the peripheral edge portion, and the degree of expansion of the sheet S is larger. Looking at this from the whole air tent A, the air tent A
In the plan view, the degree to which the sheet S expands is determined by the center line Q ₁ connecting the centers of the air tents A in the width direction in plan view
It also becomes the largest on the center line Q ₂ which connects the upper part and the center substantially in the longitudinal direction. That is, the degree of expansion of the sheet S is greatest at the intersecting portion of the center lines Q ₁ and Q ₂ (the topmost portion T of the air tent A) in a plan view, and is in a radial circle centered on the topmost portion T. Get smaller. For the reasons described above, the degree of expansion of each corner C of the four corners of the sheet S is small. As a result, even if the notches 10 are provided at the four corners of the holding net N, the corners C of the sheet S are not excessively expanded and the sheet S is not damaged. On the contrary, it is not necessary to reinforce each corner portion C of the sheet S because the missing portion 10 is provided.

The seat S of this embodiment is provided with doorways 8 near two corners C. Since the portion of the presser net N corresponding to the inlet / outlet port 8 is already missing, even if the sheet S is blown to form the inlet / outlet port 8, it does not interfere with the presser net N. Therefore, the work of removing the pressing net N due to the entrance / exit 8 becomes unnecessary, and the work efficiency can be improved. Further, the strength of the presser net N is not reduced.

Missing portions 10 are provided at the four corners of the holding net N of this embodiment. Moreover, the degree of expansion at each corner C of the sheet S is small. Therefore, when pressing a corner portion of a sheet smaller than the sheet S, by increasing the winding amount around the single pipe 11 at the peripheral portion of the pressing net N, the missing portion 1
It is possible to press 0 around each corner. Further, even if the sheet is larger than the sheet S, it can be pressed down by reducing the winding amount. In this way, it is possible to press sheets of different sizes with one presser net N without changing the sheet S, so that the number of types of presser net N can be reduced.

When this sheet S is folded and stored,
By not folding the polyethylene film F faces as much as possible and folding only the opposite faces thereof, the film F faces do not come into close contact with each other, and the sheet S is attached when the air tent A is installed next time. The work of extending becomes easy.

In this specification, the doorway 8 has been described as being provided integrally with the seat S, but only the opening / closing port of the plastic fastener is provided in the vicinity of the corner C of the seat S, and a separate portion is provided for that part. The structure may be such that a doorway of the body is attached. Further, in this embodiment, the case of the temporary air tent A has been described. However, this air tent A
May be permanently installed.

[0024]

In the air tent according to the present invention, the four corners corresponding to the corners of the sheet in the presser net are missing. Therefore, there are the following various effects.
(1) When the sheet expands, the degree of expansion at the corners of the sheet is small. Therefore, when the presser net is installed, it can be attached to seats of various sizes by adjusting the amount of winding around the single pipe at the peripheral edge thereof. In addition, when the sheet is formed, the sheet can be formed in a flat shape instead of being cut three-dimensionally, and thus the production is simplified. (2) When the door is provided at the corner of the seat, the door does not interfere with the presser net. Therefore, it is not necessary to drop the presser net for the entrance and exit, the strength of the presser net is not lowered, and the work efficiency can be improved. (3) When the sheet is formed by alternately weaving threads made of polyethylene, the weight of the sheet is significantly reduced. Therefore, a large heavy machine for transportation and installation is unnecessary, and the work can be performed only by human hands. (4) In addition, since minute irregularities are provided on the surface of the sheet opposite to the surface on which the film is attached, even if these surfaces are overlapped with each other, they do not adhere to each other. Therefore, the work of extending the sheet stored in the folded state is easy.

[Brief description of drawings]

FIG. 1 is a perspective view of an air tent A according to the present invention.

FIG. 2 is a plan view showing a state in which a seat S and a presser net N constituting an air tent A are installed on a poolside 1a.

FIG. 3 is a plan view showing a method of manufacturing a sheet S.

FIG. 4 is a partially enlarged view of a sheet S.

5 is an enlarged cross-sectional view taken along line XX of FIG.

FIG. 6 is a perspective view of a doorway 8.

FIG. 7 is a side view in which a part of a state where the sheet S is installed is cut away.

FIG. 8 is a cross-sectional view showing a state in which the sheet S is fixed to the single pipe 11.

9 is a perspective view of FIG. 8. FIG.

FIG. 10 shows the internal pressure P when the air tent A is inflated.
It is a side sectional view showing.

11 is a plan view of FIG.

[Explanation of symbols]

A: Air tent C: Corner F: Polyethylene film (waterproof film) N: Presser net P: Internal pressure S: Sheet 1a: Poolside (ground level) 1b: Concrete placing surface 4a: Warp 4b: weft 6: Multi-blade blower 7: Blower fan (blower) 8: Doorway 10: Missing part

Claims (4)

[Claims] 1. A sheet having a peripheral portion installed on the ground surface and expanded in a dome shape by a blower, and a pressing net for suppressing the expansion of the sheet by pressing the sheet from the outside. And an air tent for temporarily protecting the concrete under curing at the construction site above the concrete placing surface, the four corners corresponding to the corners of the sheet in the holding net are missing. An air tent characterized by that. 2. The air tent according to claim 1, wherein a doorway is provided at a corner portion of the seat. 3. The air tent according to claim 1, wherein the sheet is formed by alternately weaving threads made of polyethylene. 4. The waterproof film is attached only to one surface of the sheet.
Air tent described in.