Shell element, shell structure and structure forming set

Abstract

[Summary] A shell element that can be formed simply and in a short time, a shell structure using the shell element, and a structure forming set that can form the shell element simply and in a short time are provided. Resin material is foamed on the inside of thin film, a foamed material portion with bubbles being mixed is in the state of being sandwiched by the thin film and a solid layer, and tensional stress is applied to the thin film and the solid layer and compressive stress is applied to the foamed material portion, thus the shell element is difficult to be cracked or split, and the shell structure is formed by the shell element. And, the shell structure forming set forms the shell structure easily.

Claims

1. A shell element constituting a shell structure enclosing space, wherein: the shell element is composed of thin film that constitutes one side of surfaces of the shell element and a layered foamed material portion; one surface of the layered foamed material portion adheres to the thin film, thus the thin film and the layered foamed material portion are integrated; another surface of the layered foamed material portion that does not adhere to the thin film forms a solid layer with low bubble density in which bubbles escaped from the another surface; an entire surface of the solid layer facing toward the space is exposed to the space; and tensile force is applied to both of the thin film and the solid layer and compressional force is applied to the layered foamed material portion except for the solid layer.

2. The shell element according to claim 1, wherein: the shell element is curved convexly toward an outside of the space; and the layered foamed material portion adheres at least to an inner surface of the thin film.

3. The shell element according to claim 2, wherein the thin film is optically transparent.

4. The shell element according to claim 2, wherein a flame-resisting layer is formed along a shape of the shell element at least on either an outer surface of the thin film or a space-side surface of the solid layer.

5. The shell element according to claim 2, wherein the layered foamed material portion is made of foamed material either of polyurethane resin or polyisocyanurate modified resin and an expansion ratio of the layered foamed material portion except for the solid layer is more than 20 times and less than 100 times.

6. Shell structures enclosing space comprising a shell structure including the shell element according to claim 2.

7. The shell element according to claim 1, wherein the thin film is optically transparent.

8. Shell structures enclosing space comprising a shell structure including the shell element according to claim 7.

9. The shell element according to claim 1, wherein a flame-resisting layer is formed along a shape of the shell element at least on either an outer surface of the thin film or a space-side surface of the solid layer.

10. Shell structures enclosing space comprising a shell structure including the shell element according to claim 9.

11. The shell element according to claim 1, wherein the layered foamed material portion is made of foamed material either of polyurethane resin or polyisocyanurate modified resin and an expansion ratio of the layered foamed material portion except for the solid layer is more than 20 times and less than 100 times.

12. Shell structures enclosing space comprising a shell structure including the shell element according to claim 11.

13. Shell structures enclosing space comprising a shell structure including the shell element according to claim 1.

14. The shell element according to claim 1, wherein the layered foamed material portion is provided so as to be thick in a lower portion and to be thin in an upper portion.

15. The shell element according to claim 1, wherein the shell element includes a plurality of the layered foamed material portions and each of the layered foamed material portions includes the solid layer.

16. The shell element according to claim 15, wherein each of the layered foamed material portions is provided so as to be thick in a lower portion and to be thin in an upper portion.

17. A structure forming set that is characterized as follows: the structure forming set is composed of single-layered thin film, a holding means of the thin film, a spraying means of foamed material, and resin material; the thin film is integrated to form a shape enclosing space and has an opening portion to enable to open an outside and an inside of the space; the holding means of thin film closes the space by holding a peripheral edge of the thin film and enables the thin film to curve convexly toward the outside; and the spraying means of foamed material can spray the resin material mixed with bubbles on an inner surface of the thin film that is curved convexly toward the outside, and constructs structures, in which one surface of a foamed material portion adheres only to the inner surface of the thin film and another surface of the foamed material portion that does not adhere to the thin film forms a solid layer with low bubble density in which bubbles escaped from the another surface, an entire surface of the solid layer facing toward the space being exposed to the space.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a perspective view of the shell structure (Example 1).

(2) FIG. 2 is a plan view of the shell structure (Example 1).

(3) FIG. 3 is the first process in a forming method of the shell structure (Example 1).

(4) FIG. 4 is the second process in a forming method of the shell structure (Example 1).

(5) FIG. 5 is the third process in a forming method of the shell structure (Example 1).

(6) FIG. 6 is a sectional drawing of the shell element (Example 1).

(7) FIG. 7 is an explanatory drawing of the stress distribution (Example 1).

(8) FIG. 8 is an explanatory drawing of the stress distribution (Example 1).

(9) FIG. 9 is a sectional drawing of the shell element (Example 2).

(10) FIG. 10 is the first process in a forming method of the shell structure (Example 3).

(11) FIG. 11 is the second process in a forming method of the shell structure (Example 3).

(12) FIG. 12 is the third process in a forming method of the shell structure (Example 3).

(13) FIG. 13 is an explanatory drawing of the advertising medium (Example 4).

BEST MODE(S) FOR CARRYING OUT THE INVENTION

(14) In order to provide simply and in a short time a shell element constituting a structure that is lightweight and hardly cracked or split, a resin material is foamed and sprayed on an internal side of a thin film to make a foamed material portion. A foamed material part is sandwiched by the thin film and a solid layer with low bubble density and constitutes a unified shell element.

Example 1

(15) In example 1, a shell structure 100 is explained referring to from FIG. 1 to FIG. 6, which is one of temporary housing that integrates shell structures of approximately quadrangular pyramid 110, 120, 130, 140 composed of four shell elements with each surface being an approximately triangular shape. FIG. 1 shows a perspective view of the temporary housing, and FIG. 2 shows a plan view of the temporary housing. FIG. 3 shows explanatory drawings of a forming method of the shell elements. FIG. 6 shows a sectional drawing of location A-A in FIG. 2. FIG. 7 and FIG. 8 show the stress distribution of location B-B in FIG. 6, FIG. 7 shows stress distribution of the state without external force being applied and FIG. 8 shows stress distribution of the state, in which bending moment is occurring caused by pressing force of wind and so on.

(16) The shell structure 100 is composed of an entry space into a living space, the living space integrating a sleeping space 2 and a dining space 3, and a hygienic space 4 that use water for a toilet and so on. The entry space 1 has a doorway 11 which enables entry from the outside and can be opened and closed by the engagement of touch fasteners 10 that prevent intrusion of rain or wind from the outside. The doorway 11 is composed of only the thin film without foamed material portion being adhered.

(17) The thin film (refer to FIG. 6) uses a non-woven sheet having waterproofing moisture-permeable property, on which polyethylene superfine filaments of 4 m average diameter are laminated and bound by only heat and pressure, and intends to prevent internal dew condensation of the foamed material portion. Seaming together the ridgelines of the thin film made of approximately triangular non-woven sheet makes four shell structures forming approximately triangular shapes with a different inclination of the ridgeline.

(18) Furthermore, joining portions 111 integrating four shell structures 110, 120, 130, 140 are cut off beforehand, and seaming together the joining portions 111 unifies the inside of four shell structures. Seaming of the joining portions can be done by chemical fiber threads or fasteners. The thickness of thin film shall be from 0.3 mm to 1.0 mm, and optical-transparent performance is given to the thin film depending on the thickness.

(19) Inside of the thin film 30, rigid polyurethane foamed resin is sprayed by spray nozzles and forms a foamed material portion 40. The expansion ratio shall be from 20 times to 100 times, but the ratio of from 30 times to 50 times is preferable from the viewpoint of ease of spraying work and strength and rigidity of the foamed material portion. Although rigid polyurethane foam is used due to ease of on-site operation, depending on the working environment of spraying, for example in the case of producing shell elements beforehand in a factory, polystyrene resin or polyolefin resin can be used.

(20) Foamlite (registered trademark) manufactured by BASF INOAC Polyurethanes Ltd. is used for the rigid polyurethane foam resin. Foamlite is composed of two liquid ingredients, polyol ingredients including a polyol and other additives, and polyisocyanate ingredients. When polyurethane foam resin is sprayed, the foamed resin solidifies in several tens of seconds and becomes the state that air escaped from bubbles on the sprayed inner surface side, thus forms a solid layer (refer to FIG. 6) with low bubble density on the sprayed inner surface side.

(21) Although the thickness of solid layer 41 differs depending on the sprayed thickness in one time of rigid polyurethane foam resin, in the case that the foamed material portion of rigid polyurethane foam resin with the thickness of 15 mm to 20 mm is sprayed, the solid layer of 0.5 mm thickness is formed on the surface of the foamed material portion. The solid layer 41 is a layer of high material density with air escaping from bubbles, has allowable tensile stress equivalent to the resin material, and is hardly broken.

(22) In the upper portion of the thin film 30, an optically transparent portion 50 without the foamed material being sprayed is configured. Since the optically transparent portion 50 is only made of thin film having optical transparency, in the case that the external space is lighter than the internal space of the shell structure 100, the light transmits from the outside to the inside, and in the case that the external space is darker than the internal space of the shell structure 100, the light used in the internal space transmit outside. In the case of the shell structure being used as a temporary structure, the internal usage condition appears outside.

(23) Also, in the living space 2, 3 inside of the shell structure 100, foods can be heated up by using simple warming equipment, such as a burner, an electric cooking device and so on, and a heat insulating mat is used as bedding, thus a minimum level of living is made possible. A nonflammable coating material is painted inside the shell element 20, thus the shell element becomes hardly flammable. Ventilation associated with the living of people is done through a ventilating part 51 in the upper portion and a ventilating part 52 in the lower portion. Also, the ventilating part 51 for exhausting air is installed in the hygienic space too. A partition film 5 is installed between the entry space 1 and the living space 2, 3, thus living is possible even leaving the doorway 11 open depending on the season.

(24) Here, referring to from FIG. 3 to FIG. 5, the constructing method of the shell structure 100 is briefly explained. The thin film 30 constituting the shell structure is integrated by seaming together beforehand. For the first process, the lower opening part 21 of the seamed thin film is fixed by nails or an adhesive agent to a wooden foundation 22 forming the periphery so that the opening is closed. In the state of the lower opening part 21 being fixed to the wooden foundation 22, the doorway 11 is also closed by touch fasteners, etc., then the thin film 30 covers over the wooden foundation 22 in a slackened condition (refer to FIG. 3).

(25) For the second process, air is pressurized and poured into the inside of the space enclosed by the closed thin film by an air-pressurizing means 23 (refer to the outlined arrow in FIG. 4). By the inside of the space being pressurized by poured air (refer to the fine-lined arrows in FIG. 4), each surface constituting the shell element 30 becomes the expanding state convexly outside (refer to FIG. 4).

(26) In this state, while pouring air into the inside of the space, workers enter the space by opening the doorway 11, and the expanding state of the shell element 30 convexly outside is maintained even after closing the doorway 11. Then, for the third process, the workers spray foamed resin by a spraying means of foamed material 24 on the internal surface of the thin film 30 from lower portion successively upward (refer to FIG. 5).

(27) The sprayed foamed resin becomes the state that the solid layer 41 (refer to FIG. 6) is formed on the surface in several tens of seconds, thus the rigidity is secured. The lower portion of the thin film 30 with the foamed resin being sprayed on the surface stabilizes the shape in a short time and becomes a self-standing state, thus spraying upward becomes easy. For the optically transparent portion 50, a frame is attached so that foamed resin is not sprayed. In the state that the first layer of the foamed material portion is formed by spraying the first layer of foamed material, the solid layer 41 with low bubble density is formed on the internal surface of the foamed material part 40 of the first layer of the foamed material portion.

(28) Furthermore, the second layer of foamed resin is sprayed up to the middle height of the space enclosed by the thin film. After the solid layer 43 of the second layer is formed, again, the third layer of foamed resin is sprayed until the lower height (refer to FIG. 6). Up to the lower height, the internal surface of the thin film 30 becomes the state that three layers of foamed material portions where the foamed material part 40, 42, 44 are overlapped with the solid layers 41, 43, 45 are formed.

(29) Here, with reference to FIG. 7 and FIG. 8, internal stress acting on the virtual cutting section of location B-B in FIG. 6 of the portion that the three layers of foamed material portions are formed is explained. FIG. 7 shows internal stress in the state in which no external force of the wind, etc. acts on the shell element 20. Since the thin film 30 is in the expanded state convexly outside, tensile stress (refer to a bold-lined arrow (a)) remains. Inside the foamed material part 40 of the first layer, since solidification occurs while expanding due to foaming, compressive stress (refer to an outlined arrow (b)) remains. On the solid layer 41, tensile stress (refer to a bold-lined arrow (c)) remains, since air is released from bubbles and contraction occurs before solidification.

(30) Spraying work of foamed resin for the second layer is carried out after solidification of the first layer is stabilized. As similarly as the first layer, since the foamed material part 42 also solidifies while expanding, compressive stress (refer to a bold-lined arrow (d)) remains, tensile stress remains on the solid layer 41 of the first layer, and tensile stress (refer to a bold-lined arrow (e)) remains on the solid layer 43 too. Similarly in the third layer too, compressive stress (refer to a bold-lined arrow (f)) remains in the foamed material part 44, and tensile stress (refer to a bold-lined arrow (g)) remains on the solid layer 45.

(31) Next, the state in which pressing force caused by external force of wind and so on acts on the shell element 20 is explained referring to FIG. 8. Bending moment develops at the location B-B in FIG. 6, tensional force acts at the third layer location on the inward side, and compressional force acts at the first layer location on the outward side. Then, tensile stress (refer to a bold-lined arrow (g0)) on the solid layer 45 of the third layer, since tensional force is added by the applied external force, becomes larger than the tensile stress (refer to a bold-lined arrow (g)) in the case with no external force being applied, and compressive stress (refer to an outlined arrow (f0)) in the foamed material part 44 of the third layer becomes smaller than the compressive stress (refer to an outlined arrow (f)) in the case with no external force being applied.

(32) However, the solid layer 45 of the third layer does not break until tensile stress reaches the allowable tensile stress equivalent to the resin material constituting the foamed material portion. Then, until the solid layer 45 of the third layer breaks, tensional force does not act on the foamed material part 44 of the third layer, thus the effect that even the portion with high bubble density that is easy to be cracked or split by tensional force does not crack or split is realized.

(33) Additionally, when external force of wind and so on becomes larger and the solid layer 45 of the third layer breaks due to the increased bending moment, cracks develop on the internal space side and breakage occurs inside the foamed material part 44 with small allowable tensile stress. And, the tensile stress (refer to a bold-lined arrow (e0)) acting on the solid layer 43 of the second layer increases more than the tensile stress (refer to a bold-lined arrow (e)) in the case with no external force being applied, and compressive stress (refer to an outlined arrow (d0)) in the foamed material part 42 of the second layer becomes smaller than the compressive stress (refer to an outlined arrow (d)) in the case with no external force being applied.

(34) However, since the shell element 20 is curved convexly toward outside, even if cracks occur on the foamed material part 44 and the solid layer 45 of the third layer, the shell element 20 hardly protrudes convexly toward the inside, also cracked portion of the third layer is difficult to spread to the collapse of the whole shell structure 110 at once, and since layers are overlapped, the shell structure 110 (refer to FIG. 1 and FIG. 6) is difficult to collapse and maintains stable condition. Furthermore, in the case that external force to pull the shell element 20 outside occurs, tensile force acts on the outside layer and compressional force acts on the inside layer. However, similarly as in the case that pressing force is applied by wind and so on, the shell structure is difficult to collapse and maintains a stable condition.

Example 2

(35) In example 2, with reference to FIG. 9, a shell structure 200 composed of a shell element 60 of the same sprayed layers from the lower portion to the upper portion and with the sprayed thickness that is made thick in the lower portion and thin in the upper portion is explained.

(36) For the shell element in example 2, three layers of foamed material portion 61, 62, 63 are sprayed from the lower portion to the upper portion on the inner side of the thin film. Each layer of the foamed material portion is sprayed thick in the lower portion and thin in the upper portion respectively. Specifically, each layer is sprayed 20 mm to 30 mm thick in the lower portion, each layer is sprayed so that the upper portion becomes thinner, and 8 mm to 10 mm thickness is sprayed in the upper portion.

(37) In the shell element 60 constituting the shell structure 200, stress relation similar to the internal stress of the shell element 20 in example 1 that was explained at the location B-B in FIG. 6 appears at each portion from the lower portion to the upper portion. In the case that force of wind and so on from the outside is applied to the shell structure 200, since large stress develops in the lower portion of the shell structure 200, the thickness of the lower portion of the shell element 60 is made thick. The used quantity of resin material is saved by varying thickness of each portion of the shell element according to the magnitude of internal stress developed by external force. Furthermore, since the thickness of each portion of the shell element varies gradually from the lower portion to the upper portion, there is no portion where internal stress discontinuously changes, and occurrence of crack or split against external force from the outside is more difficult.

Example 3

(38) In example 3, with reference to from FIG. 10 to FIG. 12, an explanation is made about a shell structure 300 that can respond even to the case where the air-pressurizing means (refer to FIG. 4) cannot be run due to no available electric power. For the first process, the thin film is to be prepared, in which rings 71, 71, . . . are sewn on each ridge of the thin film 70 constituting the shell structure 300 (refer to FIG. 10). Moreover, rings are also sewn on the external surface of the thin film 70 between rings 71 and 71 lined up horizontally (a drawing is omitted).

(39) For the shell structure 300 in example 3, the lower opening of the thin film 70 may not be fixed on the wooden foundation 22 (refer to FIG. 4) and may be buried in the soil or left open. For the second process, in order to make the thin film 70 in the state of being expanded convexly outside, rods 73 with superior restoration property such as carbon fiber or glass fiber shall be inserted through the rings 71, 71, . . . on the ridges in a manner of intercrossing horizontally and vertically, and the rods 73 shall be deformed so that the thin film becomes the state of being expanded convexly outside.

(40) More specifically, after inserting the rods 73 through the rings 71 vertically, the rods 73 shall be curved by the way such as burying the lower portion of the rods 73 and binding the upper portion of the rods 73, thus the thin film 70 shall be made in the state of being expanded convexly outside (refer to FIG. 11). Furthermore, although shown in broken lines in FIG. 11, the rods 74 shall be inserted in a horizontal direction into the rings 71 lined up horizontally while curving the rods gently, then making the thin film 70 in the state of being expanded convexly outside with the rods of both vertical and horizontal directions is preferable.

(41) And, similarly as in example 1 or example 2, it is the same to foam and spray resin material on the internal surface of the thin film 70 and adhere foamed material portion 75 (refer to FIG. 12) on the internal surface of the thin film 70 for the third process. With encapsulating resin material and liquid air into a storing box 76 beforehand, it is good to foam the resin material by ejected liquid air in the storing box 76.

(42) Although drawings are omitted, if the structure forming set, which contains the rods as a thin film holding means and resin material encapsulated in the storing box and liquid air encapsulated inside of the storing box as a spraying means of foamed material, is always made available at evacuation places at the time of disaster, shell structures can be easily provided and preferable at emergency such as at the time of disaster. Furthermore, after forming shell structures, the rods are taken out from the rings 71 and can be reused to form other shell structures.

Example 4

(43) In example 4, with reference to FIG. 13, a floating advertisement 400 with optical-transparency performance is explained. For the floating advertisement 400 fixed by an anchor 81, a foamed resin is sprayed on the thin film except for a message-transmitting portion 80 toward outside. Moreover, inside the floating advertisement 400, an illumination means (drawings are omitted) composed of LED lights and an electric power source is installed.

(44) Since the floating advertisement is the size that foamed resin cannot be sprayed from the inside of thin film and a foamed material portion cannot be formed inside of the thin film, a foamed resin is sprayed on the thin film from the outside while the thin film is expanded by blowing air into the thin film. Making the thickness of thin film thin, making the thickness of foamed material portion thin, and enclosing lighter gas than air into the internal space enable to use as a floating advertisement. Compared with a floating advertisement that encloses lighter gas than air into the inside of the thin film, the shell element is difficult to be damaged by birds, etc., thus has superior stability as an advertisement medium.

(45) (Others) Although an example in the case of constructing a shell structure on site is explained in each example, it is also a good idea to form shell elements beforehand in a factory and so on and joint them at the site. Moreover, although examples of shell structures of three layers are shown, the number of layers is surely not restricted and can be one layer or more than four layers depending on the scale of shell structures. Dimensions shown in the examples are merely examples and are certainly not restricted. The intended use of temporary structures that the present invention applies is not restricted to structures aimed for housing, but may be structures aimed for food storage or a morgue. The embodiments disclosed here are illustrative examples in all respects, and it should be considered that the embodiments are not restrictive. The technical scope of the present invention is shown by claims without being restricted to the above explanation, and all modifications are intended to be included in the same meaning and range as the claims.

REFERENCE SIGNS LIST

(46) 100, 110, 120, 130, 140, 200, 300 . . . shell structure, 111 . . . joining portion, 1 . . . entry space, 2 . . . sleeping space, 3 . . . dining space, 4 . . . hygienic space, 5 . . . partition film, 10 . . . touch fastener, 11 . . . doorway, 20 . . . shell element, 21 . . . opening part, 22 . . . wooden foundation, 23 . . . air-pressurizing means, 24 . . . spraying means of foamed material, 30 . . . thin film, 40, 42, 44 . . . foamed material part, 41, 43, 45 . . . solid layer, 50 . . . optically transparent portion, 51, 52 . . . ventilating part, 60 . . . shell element, 61, 62, 63 . . . foamed material portion, 70 . . . thin film, 71 . . . ring, 73, 74 . . . rod, 75 . . . foamed material portion, 76 . . . storage box, 400 . . . floating advertisement, 81 . . . anchor, 80 . . . message portion