JP3580301B2 - Reinforcing method of membrane body opening - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for reinforcing an opening of a membrane such as a membrane structure building, and more particularly, to a technique of forming a membrane opening formed on a membrane formed by applying a resin coating or lamination to a base fabric of a fiber fabric. Related to reinforcement method.
[0002]
[Prior art]
Membrane structures such as dome ceilings and tent houses, storage bags made of membranes (for example, flexible container bags), or membranes used for gas containers such as balloon spheres and airship hulls, may be used to cover It is necessary to withstand the pulling force associated with the working force of the installation rope, wind pressure, gas pressure, etc., and withstand ultraviolet rays, acid rain, snowfall, and the like. Therefore, these film bodies are resistant to tension and internal and external pressures, and have excellent weather resistance, water resistance, and cold resistance, and also have excellent airtightness as necessary. A film formed by coating or laminating a synthetic resin, a synthetic rubber, or the like on a base fabric of a fiber woven fabric having a plain weave structure woven by the method described above. In addition, these membranes are provided with openings of various sizes everywhere for the purpose of lighting, venting, maintenance, air supply / exhaust, gas injection, and other purposes, in addition to the rope insertion holes for tensioning.
[0003]
By the way, in the film body having the above-described structure, unlike a film body having a single uniform structure such as rubber, for example, a structure in which the fiber woven fabric is a direct strength member, the tension and pressure acting on the film body. The principal stress associated with is generated along the direction of the warp and / or weft of the woven fabric, and the diagonal component is limited to within the supporting force depending on the entanglement of the warp and the weft of the base fabric and the holding action of the coating or laminating agent. And the ability to transmit stress in the oblique direction is slight.
[0004]
Furthermore, in a membrane formed by coating or laminating a resin or the like on a base fabric of a woven fabric, the warp and the weft of the base fabric cut by forming the opening are directly connected to the warp and the weft on opposite sides of the opening. It becomes impossible to transmit the stress, and the stress acting on the membrane body is gradually transmitted from the position far from the opening to the opening, bypassing the warp and weft of the base cloth near the opening, and transmitted again to the base fabric structure on the opposite side of the opening. There is such a property.
FIG. 6 schematically shows how the stress is transmitted at the opening. FIG. 6 shows an opening 63 of a membrane formed by coating or laminating a resin on a plain fabric 60 woven by warp 61 and weft 62, and a hollow arrow along the warp 61 of the membrane base fabric. The load W acts in the direction, and the load W causes the typical warp (signs a, b, c, d, e, f, g, h, i, j, k, and k) of the base cloth near the opening 63 and both sides thereof. FIG. 4 is a diagram showing stress acting on l) represented by σ. The acting direction of the stress σ is indicated by a double-headed arrow, and the path through which the stress acting on the warp (e, f, g, h) cut at the opening is transmitted to the opposite side across the opening is indicated by a broken line. Each change state is represented by the length of an arrow. The stress acting on the warp (e, f, g, h) cut at the opening 63 is detoured around the opening 63 along the dashed stress lines (s1, s2, s3, s4). Since the warp yarn (c, d, i, j) passing near the side of the opening 63 is transmitted to the opposite side, the yarns (e, f, g, Both of the stresses acting on h) act to generate a remarkably large stress (σ1, σ2).
The phenomenon in which stress concentration occurs on the side of the opening as described above is a phenomenon common to a film formed by coating or laminating a resin on a woven fabric base fabric, but particularly in the case of a plain woven fabric. The tendency is remarkable.
[0005]
On the other hand, in membrane structures such as dome ceilings and tent houses, storage bags made of membranes (for example, flexible container bags), or membranes used for pressure vessels such as balloon spheres and airship hulls. Generates stress due to tension and internal / external pressure acting on the film body, that is, wind pressure and gas pressure.Therefore, large stress concentration occurs around the film body opening as described above, and the film body around the opening There is a problem that the so-called tear propagation phenomenon occurs in which the base fabric fibers are not able to withstand the stress and are torn apart and propagate one after another. In the above membrane structure, a plain weave structure is often used as the base fabric constituting the membrane body, and tear propagation is particularly likely to occur.However, the film structure is not limited to a plain weave tissue base fabric, but may be made of another weave tissue base fabric. This also occurs in the case.
[0006]
Conventionally, as a method of reinforcing the opening of the membrane body, for example, a method of caulking by attaching a metal or resin ring to the inner diameter of the opening as necessary in other openings as well as the rope insertion hole is often used. . Alternatively, a reinforcing method is also adopted in which a reinforcing member (commonly referred to as "patting cloth") made of a circular or rhombic film body having an opening of the same shape as the opening of the film body formed at the center with both openings concentric. .
[0007]
In the case of the former reinforcing method using a ring, since the ring that is crimped to the opening is only pressed against the membrane and is not completely integrated with the fiber, no stress is transferred through the ring. Even if the ring and the membrane are bonded together so that they are integrated, the physical properties (rigidity, flexibility, elongation, etc.) of the membrane and the ring are extremely widened, and the bonded portion may become fatigued or stress concentrated. It is fully assumed that the membrane peels off early and breaks from the peeled wound, and can withstand only a very low stress level.
[0008]
On the other hand, in the latter reinforcing method using a circular or diamond-shaped “patting cloth”, a film body obtained by resin-coating or laminating a woven fabric having the same structure as the film body body is used as the padding cloth, and the film body is applied to the film body. Even in the case where the fabrics of both fabrics are stuck so as to cross each other so as not to be in the same direction, a sufficient reinforcing effect may not be obtained.
The reason is that the woven fabric can withstand a large stress in the warp and weft directions, but can resist only a small stress in the diagonal direction as described above. When the fabrics are adhered diagonally so that they cross each other, stress is applied to the patch in an oblique direction, so the fabric slips at the intersection of the warp and weft of the base fabric of the patch and deforms the woven structure, causing stress transmission. It is considered that it cannot fulfill the role of.
[0009]
Therefore, in order to prevent the occurrence of tear propagation, it is necessary to make the film body of the reinforcing member a much stronger material than the film body of the main body and affix a reinforcing member that covers the periphery of the opening over a very large area. There is. However, when a reinforcing member having significantly different physical properties (for example, flexibility and elongation ratio) from the film body of the main body is used, the opening reinforcing portion has significantly different physical properties from other portions, and causes wrinkles and stress concentration. Thus, there is also a problem that the fracture occurs at a low stress level. In addition, in the case where extremely light weight, strength and reliability are required, as in the case of a gas filling hull of an airship or a film constituting a gas filling sphere of a balloon, such a reinforcing method is inappropriate. is there.
[0010]
[Problems to be solved by the invention]
In view of the above situation, the present invention attempts to solve the problem that in a film formed by resin coating or laminating a base fabric of a woven fabric, the stress concentration generated at the peripheral portion of the opening formed in the film is dispersed. A film opening that relaxes and suppresses the occurrence of tear propagation in the opening, is flexible, lightweight, has high reliability and durability, reduces wrinkling around the opening, and has an aesthetically pleasing appearance. Another object of the present invention is to provide a method for reinforcing a part.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, a film body opening formed in a flexible film body by coating or laminating a resin on a base fabric of a fiber woven fabric is reinforced by the following method.
That is, a point on the film body at an appropriate distance in a direction opposite to the warp direction and / or the weft direction of the base fabric constituting the film body from a substantially center position of the opening formed in the film body. Are a pair of starting points, and from each of the starting points, along two straight lines passing through the vicinity of the outer edge of the opening and on the outer side opposite to the opening, a strip-shaped reinforcing member having flexibility similar to the film body Are arranged in a V-shape, and the front ends thereof cross each other at the opening sides, and the reinforcing member is reinforced by welding, bonding, or sewing to the film body.
[0012]
Alternatively, in the above, a pair of the band-shaped reinforcing members each extending from the starting point to both sides of the opening outer edge are further extended from the starting point in the direction opposite to the opening, and the respective crossing points substantially cross each other at the starting points. It may be reinforced in shape.
[0013]
The above-mentioned reinforcing method is applied to an opening formed for a specific application purpose on a membrane body, but is also applied to an opening formed by cutting and shaping a damaged portion generated in the membrane body into an appropriate shape. Can be.
[0014]
Each of the above reinforcing methods disperses the stress in the opening along the direction of the reinforcing member, bypasses the opening and transmits the stress to the opposite side of the opening, and prevents the occurrence of stress concentration at the periphery of the opening and tears. Propagation can be suppressed.
[0015]
The reinforcing member is formed by coating or laminating a resin on a base fabric of a fiber woven fabric, and using a flexible film body, in any one of the warp direction and the weft direction of the base fabric constituting the film body. It is preferable that the reinforcing member is made of a lightweight and flexible material, and the stress acting on the warp and the weft cut at the opening is prevented along the reinforcing member so as to avoid the opening. To the other side. The reinforcing member is preferably made of the same material as the film body to be reinforced and having a width of about 70% or more of the opening width of the opening, and more preferably substantially equal to the opening width. Thereby, the stress level of the reinforcing member can be reduced, the reliability and the durability can be increased, and the reinforcing portion can be made flexible so that effective reinforcing can be performed.
[0016]
The angle between the openings of the reinforcing members arranged in a V-shape or X-shape is defined as the angle formed by a straight line passing from the starting point and passing near the outside of the opening outer edge and a straight line passing from the same starting point to the center of the opening. It is preferable that each of them is 30 ° or less, and it is even more preferable that the starting point be a point of 22 ° 30 'or less. Thus, the stress in the direction along the reinforcing member is suppressed to a low level, the centripetal force toward the opening due to the stress acting on the reinforcing member is reduced, and deformation of the opening and generation of wrinkles are prevented.
[0017]
On the other hand, a plain weave fabric has a simple woven structure in which warp and weft alternately cross over each other and has no complicated entanglement, and the stress acting on the fabric is oblique in the diagonal direction not along the warp and weft. The structure is particularly difficult to transmit as compared with the case of the woven structure of the woven fabric, and the tendency of tear propagation at the opening is high. Therefore, it is particularly desirable to apply the above-described reinforcing method according to the present invention to the opening formed in the film body in which the base fabric constituting the film body has a plain weave structure.
However, the film body constituting the film body to be reinforced by the present invention is not limited to the base cloth having a plain weave structure, and is not limited to the base fabric having a plain weave structure. It also includes all fabrics made of woven fabric.
[0018]
In the membrane used for the membrane structure, the base fabric is not limited to the woven fabric structure. For example, a warp plane formed by arranging warps in a plane at substantially equal intervals and a weft are arranged in a plane at substantially equal intervals. The two planes of the weft plane are overlapped with each other so that the yarn directions cross each other to form a two-layer fiber plane, and the upper and lower surfaces of the two-layer fiber plane are coated with resin or laminated with a thin resin film. In some cases, a film formed by bonding and integrating the two-layer fiber planes and forming a surface protective layer by pressing resin may be used. Even when the method of reinforcing the opening of the membrane body of the present invention is applied to the opening of the membrane body having such a configuration, the same operation and effect as those of the membrane body having the above-described woven fabric as a base fabric can be obtained.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, some embodiments of the method for reinforcing the film body opening of the present invention will be described in more detail with reference to the accompanying drawings, but the present invention is not limited to the accompanying drawings and satisfies the requirements described in the claims. It includes all of the embodiments.
[0020]
FIG. 1 shows a first embodiment of a method for reinforcing a film body opening according to the present invention, and the reinforcing method of FIG. 1 will be described in detail below. FIG. 1 shows a part of a membrane structure. The membrane 1 is formed by coating a resin 3, 3 on the front and back of a plain fabric base cloth 2 as shown in cross section in FIG. Has a structure with excellent water resistance, weather resistance, etc. The longitudinal direction (arrow AA direction) of FIG. 1 is a direction along the warp of the base fabric 2 constituting the membrane, the horizontal direction (arrow BB direction) is a direction along the weft, and the membrane 1 An opening 4 is formed. 1 is applied when a tensile stress acts in the warp direction, and the membrane is separated from the center position of the opening 4 by an appropriate distance in the opposite direction along the warp direction of the base fabric 2. A pair of upper and lower points on the body 1 are defined as starting points 5 and 5a, and the membrane is formed along two straight lines on the left and right passing through the vicinity of the outer edge of the opening 4 from each of the starting points 5 and 5a and on the outer side opposite to the opening 4. Reinforcing members 7, 7a, 8, 8a formed of the same material as the body 1 are arranged in a V-shape as shown in FIG. The sides 6 and 6a intersect with each other (that is, the ends of 7, 8 and the ends of 7a, 8a intersect), and the reinforcing members 7, 7a, 8, 8a Heat-welded to body 1.
[0021]
In the above, the resin 3, 3 may adopt a method of laminating (welding) a thin resin film in addition to coating, and the present invention is not limited to the coated film body, but also includes reinforcement of the laminated film body, The thickness of the resin 3 is usually 10 to 30 μm, but the present invention is not limited to the thickness of the resin of the film body.
[0022]
In addition, the double-headed arrow C written on the belt-shaped reinforcing member indicates the warp or weft direction of the membrane base fabric constituting the belt-shaped reinforcing member, and all the band-shaped reinforcing members have their longitudinal directions along the warp or weft direction of the base fabric. This is the same in FIGS. 2, 3 and 4 described later.
[0023]
In FIG. 1, the base ends of the reinforcing members 7 and 7a on the starting point 5 side and 8 and 8a on the starting point 5a side are cut obliquely as shown in the drawing, and a straight line X passing through the center of the opening 4 and along the warp direction is formed. At the intersection points 9 and 9a, and the angle θ between each reinforcing member and the straight line X is 22.5 °. However, the mounting angle θ of the reinforcing member with respect to the straight line X is optimally 22.5 °, but is not limited thereto and may be 30 ° or less.
[0024]
With regard to the base fabric 2 constituting the membrane body 1, a plain weave structure is generally used as a woven structure, but the present invention is not limited to this, and various woven structures may be employed. Any suitable fiber such as polyaramide-based, polyester-based, or polyvinyl alcohol-based fibers may be used. On the other hand, as the resin 3 to be coated or laminated on the base fabric 2, an ethylene tetrafluoride resin is generally often used when the base fabric is glass fiber. In addition, a vinyl chloride resin, chloroprene rubber, Various resins such as chlorosulfonated polyethylene rubber and similar materials (including those with a fluororesin film bonded to the surface) are used, and when coating with titanium oxide for the purpose of maintaining antifouling properties, In some cases, an acrylic emulsion to which metal powder is added is coated. For some hull membranes of airships, Zylon fiber (polyparaphenylene benzobisoxazole (commonly called "PBO") is liquid crystal spun from the necessity of ultra-lightweight, outstanding durability, and high reliability. As a fiber, there is also a special example in which a film body obtained by coating or laminating a polyurethane resin on a base cloth of Zylon (trade name of Toyobo Co., Ltd.) is used.
The membrane 1 generally has slightly different tensile strengths in both the warp direction and the weft direction depending on the fabric structure of the base fabric 2, and the direction is set in consideration of this characteristic in the design of the membrane structure. In some cases.
[0025]
In the example of FIG. 1, the width of the reinforcing members 7, 7a, 8, 8a is made substantially equal to the diameter of the opening 4. However, the width of the reinforcing member is related to the mounting angle θ of the reinforcing member and the strength ratio between the reinforcing member and the membrane 1, but when the reinforcing member is made of the same material as the membrane, it is about 70% or more of the diameter of the opening 4. When the strength of the reinforcing member is low or the mounting angle θ is large, the width of the reinforcing member is set to be wider than 70%. Explaining the basis for setting the width of the reinforcing member to about 70% or more of the diameter of the opening, the force borne by one reinforcing member is half of the force acting on the entire warp cut at the opening 4, and this is The ratio converted to the mounting angle (θ) direction is 1 / (2 × cos θ), and when θ is the maximum of 30 °, the value of the previous equation is about 0.58, that is, 58%, and the strength ratio between the warp and the weft. In consideration of the above, the opening width is set to about 70% or more with a margin of about 20%.
[0026]
However, regarding the width of the reinforcing member, when the mounting angle θ of the reinforcing member is smaller than 30 °, when the reinforcing member uses a material stronger than the film base material, for example, when the reinforcing method as shown in FIG. Alternatively, when the film body acting stress is small and the required strength of the reinforcing member is low, the width may be narrower than the above, and the present invention does not limit the width of the reinforcing member to only 70% or more of the opening width. Absent.
[0027]
The reinforcing member is not limited to the same material as the film body, but is formed into a strip shape using an appropriate material as long as it is a film-like material having similar flexibility, tensile strength and elongation as the film body 1. The method of attaching the reinforcing member to the film body 1 is not limited to welding, but may be any method such as adhesion or sewing, or a combination thereof.
[0028]
In the above description, the structure, material, and characteristics of the membrane, the material of the reinforcing member, the method of attaching the reinforcing member to the membrane (excluding the arrangement), the mounting angle range of the reinforcing member, and the width of the reinforcing member are described. The dimension ranges are common to all of the other embodiments described below, and in the following description of the other embodiments, descriptions of these overlapping contents will be omitted.
[0029]
Next, the operation of the method for reinforcing the opening of the membrane shown in FIG. 1 will be described.
When a tensile force acts on the membrane body 1 in the warp direction of the base fabric 2, that is, the AA direction, almost uniform tensile stress acts on each warp of the base fabric structure, and the warps are balanced. The stress acting on the warp in the bent portion is applied to the opening 4 of the membrane 1 through a pair of opposed reinforcing members 7, 7a and 8, 8a which are heat-welded in a substantially V-shape so as to sandwich the opening. Bypassing to the other side to keep balance.
[0030]
That is, the stress acting on the warp cut at the opening 4 is near the intersection 9 of the reinforcing members 7 and 7a, the stress of the warp in contact with the reinforcing member 7 is on the reinforcing member 7, and the stress of the warp on the reinforcing member 7a is It is transmitted separately to the reinforcing members 7a, and reaches the left and right sides 6, 6a of the center of the opening 4 along the reinforcing members 7, 7a. Then, the stress is transmitted to the counterpart reinforcing members 8, 8a symmetrically arranged with the reinforcing members 7, 7a with the opening 4 therebetween, reaches the intersection 9a of the reinforcing members 8, 8a along the reinforcing members 8, 8a, and again. It is transmitted to the side of the warp cut at the opening 4 of the membrane 1. That is, the stress borne by the warp cut at the opening 4 bypasses the opening 4 along the two sets of V-shaped reinforcing members 7, 7a and 8, 8a that face each other across the opening 4 and overlap each other. It is transmitted to the warps on the opposite sides of the opening to keep the balance. Due to this action, no stress concentration occurs at the peripheral portion of the opening 4 and no tear propagation occurs on the sides 6 and 6a of the opening.
[0031]
Actually, some disturbance phenomena other than the above are accompanied, but the main method of transmitting the stress is as described above. Disturbance of the stress transmission is such that it does not reach a level that has a dangerous effect on the film strength. is there.
[0032]
Next, a second embodiment of the present invention is shown in FIG. FIG. 2 is a modified embodiment of FIG. 2, which is applied as a method of reinforcing a membrane opening when a large opening or a stress level is particularly large.
In FIG. 2, the direction of arrow AA is the direction along the warp of the base fabric 2 constituting the membrane, the direction of arrow BB is the direction along the weft, and the opening 1 is formed in the film 1. . 2 is applied when a tensile stress acts in the warp direction, that is, in the AA direction in the same manner as in FIG. 1, and extends from the center position of the opening 4 along the warp direction of the base fabric 2. A pair of upper and lower points on the film body 1 which are separated from each other by an appropriate distance in opposite directions are defined as starting points 5 and 5a, and along each of two right and left straight lines passing near the outer edge of the opening 4 from the starting points 5 and 5a. In addition, reinforcing members 17, 17a, 18, 18a each formed by forming the same material as the film body 1 in a band shape having substantially the same width as the diameter of the opening 4 are arranged on the outer side opposite to the opening 4 as shown in the figure. At the same time, the front ends of the reinforcing members intersect with each other at the right and left sides 6 and 6a of the opening 2 (that is, the front ends of 17 and 18 and the front ends of 17a and 18a intersect). , 17a, 18 and 18a are shown in the drawing. As described above, the points 17 and 17a and the points 18 and 18a are substantially X-shaped at the intersections 19 and 19a with the straight line X passing through the center of the opening 4 and extending in the warp direction with respect to the starting points 5 and 5a. And the angle θ between each reinforcing member and the straight line X is 22.5 °. The reinforcing members 17, 17a, 18, 18a are thermally welded to the film body 1 in the above-described arrangement posture.
[0033]
In the method of reinforcing the opening of the film body shown in FIG. 2, the action, that is, the way of transmitting the stress is almost the same as that described in FIG. 1, and the tensile force is applied to the film body 1 in the warp direction of the base cloth 2, that is, in the AA direction. , The warp in the base fabric structure is balanced by applying a substantially uniform tensile stress, but the stress acting on the warp at the portion cut at the opening 4 is Along the two sets of X-shaped reinforcing members 17, 17a and 8, 8a which are opposed to each other so as to overlap and are heat-sealed to the film body 1, they bypass the opening 4 and are transmitted to the warp yarns on the opposite sides of the opening to keep the balance. . Due to this action, no stress concentration occurs at the peripheral portion of the opening 4 and no tear propagation occurs on the sides 6 and 6a of the opening.
[0034]
Since the reinforcing members are attached to each other at an angle θ with respect to the straight line X, when a tensile stress is transmitted from the film body 1 to the reinforcing members 17 and 17a and 18 and 18a, the reinforcing members 17 at the intersections 9 and 9a. And 17a and 18 and 18a act as a pulling force in the horizontal outward direction which is sinθ times the force transmitted in the longitudinal direction. In the method of reinforcing the opening of the membrane shown in FIG. 2, unlike the case of FIG. 1, the base end of the reinforcing member extends further to the opposite side of the opening 4 than the intersections 9 and 9a, and the reinforcing members on the left and right at the intersections 9 and 9a. The horizontal forces (17 and 17a and 18 and 18a) intersect in an X-shape, so that this horizontal force is transmitted to the weft of the base fabric 2 of the film body 1 over a wide range to some extent, and is transmitted in the weft direction. Has the effect of reducing the occurrence of stress concentration. When the stress acting on the large opening or the film body is large, the horizontal force also increases. Therefore, in such a case, the reinforcing method of FIG. 2 having the above-described operation is more suitable than that of FIG.
[0035]
Next, a third embodiment of the present invention is shown in FIG. The method of reinforcing the opening of the membrane body shown in FIG. 3 is applied when tensile stress acts in both the warp direction and the weft direction of the membrane base fabric. In FIG. 3, the direction of arrow AA is the direction along the warp of the base fabric 2 constituting the membrane, the direction of arrow BB is the direction along the weft, and an opening 4 is formed in the film 1. The reinforcing method of the membrane body opening portion includes two reinforcing groups of a warp direction reinforcing group 31, 31a and a weft direction reinforcing group 32, 32a.
The warp direction reinforcing groups 31 and 31a have a pair of upper and lower points on the membrane 1 at an appropriate distance from the center position of the opening 4 in opposite directions along the warp direction of the base fabric 2 in the opposite direction. 5a, along the two straight lines on the left and right passing through the vicinity of the outer edge of the opening 4 from each of the starting points 5 and 5a, and on the outside opposite to the opening 4, the same material as the film body 1 is made substantially the same as the diameter of the opening 4. Reinforcing members 37, 37a, 38, and 38a each formed in a strip shape having a width are arranged as shown in the drawing, and the front ends of the reinforcing members intersect each other at right and left sides 6 and 6a of the opening 2 ( That is, the leading ends of 37, 38 and the leading ends of 37a, 38a intersect with each other), while the base ends of the reinforcing members 37, 37a, 38, 38a are positioned with respect to the starting points 5, 5a as shown in the figure. Extends to the opposite side of the opening 4 37 and 37a and 38 and 38a substantially cross each other at intersections 39 and 39a with the straight line X passing through the center and along the warp direction, and the angle θ between each reinforcing member and the straight line X is 22.5. ° arrangement. The reinforcing members 37, 37a, 38, 38a are thermally welded to the film body 1 in the above-described arrangement posture. On the other hand, the weft direction reinforcing groups 32, 32a rotate the reinforcing member 90 ° counterclockwise around the opening 4 in the same arrangement as the warp direction reinforcing groups 31, 31a, and place the reinforcing members on the warp reinforcing groups 31, 31a. It is in the form of being stacked and thermally welded.
[0036]
Regarding the function of the reinforcing method of the membrane opening in FIG. 3, the way of transmitting stress and the function and effect in the warp direction reinforcing groups 31 and 31a are almost the same as the description of the reinforcing method of the membrane opening in FIG. The same applies to the stress component acting in the warp direction. On the other hand, in the weft direction reinforcing groups 32 and 32a, the reinforcing member is rotated only 90 ° counterclockwise around the opening 4 in the same form as the warp direction reinforcing group, so that the opening of the membrane body opening in FIG. This is the same as the description in which the warp and the weft are replaced, and effectively acts on the stress component acting in the weft direction.
Accordingly, the method of reinforcing the membrane opening shown in FIG. 3 is applied to a membrane structure in which the main stress acts on both the warp and the weft of the membrane base fabric by gas pressure from the inside such as the hull of an airship or the sphere of a balloon. It is applied to the reinforcement of the formed opening. In FIG. 3, the base points 5 and 5a are set at positions far away from the opening 4 as compared with the embodiment of FIG. This is suitable for reinforcing a larger opening. On the other hand, when this reinforcing method is applied to a smaller opening, there is an effect that a large area free stress-free portion can be obtained in a central portion surrounded by a reinforcing member. is there.
In other words, if such a reinforcing method is adopted at a place where an attachment such as a gas injection fitting or other metal is attached to the opening, the attachment has a degree of freedom that allows a limited range of movement. Is conveniently obtained.
[0037]
Next, a fourth embodiment of the present invention is shown in FIG. The embodiment of FIG. 4 is basically similar to FIG.
That is, in FIG. 4, the direction of arrow AA is the direction along the warp of the base fabric 2 constituting the film, the direction of arrow BB is the direction along the weft, and the opening 4 is formed in the film 1. The method of reinforcing the membrane opening includes two reinforcing groups, a warp direction reinforcing group 41, 41a and a weft direction reinforcing group 42, 42a.
The warp direction reinforcing groups 41 and 41a are formed from a pair of upper and lower points on the membrane 1 which are separated from the center position of the opening 4 by a suitable distance in the opposite directions along the warp direction of the base fabric 2 in the warp direction. 5a, along the two straight lines on the left and right passing through the vicinity of the outer edge of the opening 4 from each of the starting points 5 and 5a, and on the outside opposite to the opening 4, the same material as the film body 1 is made substantially the same as the diameter of the opening 4. Reinforcing members 47, 47a, 48, and 48a each formed in a strip shape having a width are arranged as shown in the drawing, and the front ends of the reinforcing members intersect each other at left and right sides 6 and 6a of the opening 2 ( That is, the leading ends of 47 and 48 and the leading ends of 47a and 48a intersect with each other. On the other hand, the base ends of the reinforcing members 47, 47a, 48 and 48a are positioned with respect to the starting points 5 and 5a as shown in the figure. Extends to the opposite side of the opening 4 47 and 47a and 48 and 48a intersect in a substantially X-shape at intersections 49 and 49a with a straight line X passing through the center and along the warp direction, respectively, and the angle θ between each reinforcing member and the straight line X is 22.5. ° arrangement. The reinforcing members 47, 47a, 48, 48a are thermally welded to the film body 1 in the above-described arrangement posture. On the other hand, the weft direction reinforcing groups 42, 42a rotate the reinforcing member 90 ° counterclockwise around the opening 4 in the same arrangement as the warp direction reinforcing groups 41, 41a, and place the reinforcing members on the warp reinforcing groups 41, 41a. It is in the form of being stacked and thermally welded.
[0038]
The function and effect of the method of reinforcing the opening of the membrane shown in FIG. 4 are the same as those described with reference to FIG.
In FIG. 4, the starting points 5, 5a of the warp direction reinforcing groups 41, 41a are farther away from the opening 4 than in FIG. 3, and the intersections of the reinforcing members 47 and 47a and 48 and 48a intersect substantially in an X shape. Is located on the proximal side of the reinforcing member, that is, farther from the opening 4. And the weft direction reinforcement groups 42 and 42a have the same positional relationship. By adopting such a form, it is suitable for reinforcing an opening larger than that in the case of FIG. 3, but a free portion in which a stress is not applied in a larger area than in the case of FIG. This is advantageous, for example, when attaching a hatch for maintenance or equipment loading.
[0039]
In any of the above-described methods for reinforcing the opening of the film body, the form of the upper and lower overlapping when the band-like reinforcing members are stuck to the film body is determined by the order in which the reinforcing members are stuck. It overlaps sequentially upward from the member. FIGS. 1 to 4 are views for explaining the planar arrangement relationship of the belt-like reinforcing members in the method of reinforcing the opening of the membrane body according to the present invention, wherein the overlapping of the reinforcing members according to the bonding order is set arbitrarily. Good. That is, the present invention relates to a planar arrangement of the belt-like reinforcing members to be attached to the film body surface in the method of reinforcing the film body opening, and does not specify how the belt-like reinforcing members vertically overlap. That is, in the method of reinforcing the opening of the membrane body of the present invention, the belt-like reinforcing member is attached to the membrane body by welding, bonding, or sewing, for example, in a shape as shown in FIGS. Yes, and the reinforcing member may be attached to either the front or back surface of the membrane, or may be partially attached to the front and back sides of the membrane, or may be attached to both surfaces in the same form or different forms, respectively. Or any of them.
[0040]
Next, FIG. 8 introduces an application example of the method for reinforcing the opening of the film body according to the present invention. FIG. 8A shows an example of the appearance of the airship. The film constituting the gas filling hull 51 of the airship 50 is designed to be as light as possible and to withstand gas pressure, wind and rain, sunlight, ultraviolet rays, and obstacles. It is required to have sufficient strength and weather resistance, airtightness, corrosion resistance, heat resistance, cold resistance, reliability, etc., that can withstand contact with steel. A resin coated or laminated with a special resin is used. Ancillary facilities such as a maintenance hatch 52 and a gas inlet 53 are attached to the hull 51. For this reason, openings are formed in the membranes of the installation parts of these facilities, and reinforcements that are as light as possible and exhibit the same flexibility and elongation as the membranes of the hull so that tear propagation does not occur in the openings. There is a need to do. The reinforcing method of the membrane opening of the present invention is an optimal reinforcing method for such a portion, and the above-mentioned maintenance hatch 52 and the gas inlet 53 are provided with a belt-like reinforcing member made of the same material as the membrane of the hull. 8b by heat welding or the like from the back side of the hull to reinforce it. FIG. 8B is a plan view showing the arrangement of the reinforcing member 54 attached to the inside of the hull of the gas injection port 53, and the maintenance hatch 52 is similarly formed using the reinforcing method shown in FIG. Reinforce.
[0041]
In addition, the membrane used for the membrane structure is not limited to the above-described structure, and for example, a warp plane formed by arranging warps in a plane at substantially equal intervals and a weft is arranged in a plane at substantially equal intervals. The two planes of the weft plane are overlapped with each other so that the yarn directions cross each other to form a two-layer fiber plane, and the upper and lower surfaces of the two-layer fiber plane are coated with resin or laminated with a thin resin film. In some cases, a film formed by bonding and integrating the two-layer fiber planes and forming a surface protective layer by pressing resin may be used. Since the membrane having this texture structure is not a texture in which the warp and the weft of the two-layer fiber plane are entangled, the tear propagation is more likely to occur than the base fabric composed of the fabric texture. Therefore, a remarkable reinforcing effect can be obtained by applying the method for reinforcing the opening of the film body of the present invention to the film body having such a structure.
[0042]
Next, prior to the filing of the present application, in order to confirm the effect of the method for reinforcing the film body opening of the present invention, the same method for reinforcing the film body opening as shown in FIG. A tensile strength measurement experiment was performed using the obtained test piece, and the results are introduced below.
[0043]
FIG. 7A shows a test piece of the method of reinforcing the opening of the membrane used in the experiment, and FIG. The test piece 71 of FIG. 7A is a reinforcing method similar to that of FIG. 1, and the membrane base material 71a is formed by coating urethane resin on the front and back of a plain-woven base fabric made of Zylon (see above). The dimensions are 500 mm wide × 580 mm long (distance between grip rolls of a tensile tester), and a circular opening 72 having a diameter of 21 mm is formed at the center. The tensile strength of the film base material is 1311 N / cm (film base material breaking stress / see below).
On the other hand, as for the reinforcing member of the test piece, the belt-like reinforcing member 73 molded from the same material as the film body is heat-welded to the film body base material of the test piece as shown in the figure. Is 20 mm wide, the mounting angle is 22.5 ° with respect to the vertical center line of the opening 72, and the mounting width extends over an area of 160 mm vertically and 126 mm horizontally. In the film base material 71a of the test piece, the vertical direction (open arrow direction) of the drawing is the weft direction of the film base cloth, and the longitudinal direction (double arrow direction) of the belt-shaped reinforcing member is the weft of the film base cloth. Direction.
[0044]
The test method was as follows: a tensile load was applied in the vertical direction (the direction of the white arrow) by a tensile tester, the load was gradually increased, and the load at break was measured. (= 500 mm), and the value, that is, the rupture stress of the test piece, was divided by the rupture stress of the film base material of 1311 N / cm to determine the strength ratio with the film base material.
In addition, the said film | membrane base material rupture stress (1311N / cm) is a mean value of the measured value of five times when a rupture stress is measured by separately using a 3 cm wide test piece with a tensile tester.
[0045]
The experimental results show that the strength ratio of the test piece is 63.7% on the basis of the load at the time of breaking, while the broken portion is a base material portion away from the opening reinforcing portion as shown in FIG. 7 (b). . From such a phenomenon, it is considered that the reason why the strength ratio did not reach 100% in this experiment was also affected by the accuracy of gripping the test piece by the tensile tester, and the strength ratio was increased to 100% by improving the accuracy. It is considered when approaching.
[0046]
According to the above experimental results, since the test piece was broken away from the reinforced portion, it can be said that the reinforcing method of the film body opening according to the present invention can be reinforced more than the film base material strength. The strength ratio was about 64% of the rupture stress of the base material of the film, even on the basis of the load at the time of rupture of the test piece in the experiment, which proved to be a sufficiently practical reinforcing method.
[0047]
【The invention's effect】
According to the method for reinforcing the opening of the membrane body according to the first aspect of the present invention, the stress acting on the warp and the weft cut by forming the opening of the base fabric made of the fiber woven fabric constituting the membrane is reduced by the base fabric. The point on the membrane body away from the center of the opening along the warp and / or weft is taken as one starting point and distributed to two belt-like reinforcing members arranged in a substantially V shape from this starting point toward both ends of the opening. And transmitted along the reinforcing member. The stress is transmitted to the opposite V-shaped reinforcing member symmetrically arranged with the reinforcing member crossing each other on both sides of the opening (that is, bypassing both sides of the opening), and converged at the other starting point symmetrical to the starting point. Further, the stress is transmitted to the warp and / or weft of the film body on the side opposite to the opening with respect to the other starting point. As described above, most of the stress at the peripheral edge of the opening of the film body is transmitted to the opposite side of the opening via the reinforcing member, so that no stress concentration occurs at the opening and tear propagation can be prevented.
[0048]
In the invention according to claim 2, the belt-shaped reinforcing member extends to the opposite side to the opening at each starting point at the opposing position with the opening interposed therebetween, and the reinforcing members also cross each other in an X-shape at the respective starting points. In this way, the stress is easily distributed evenly to the two reinforcing members, and the intersection of the reinforcing members on the base point side also opposes the tensile stress in the direction orthogonal to the warp or weft direction to be reinforced. It is even more effective.
[0049]
In any of the first and second aspects, setting the starting point of the belt-shaped reinforcing member to a point far away from the opening has an effect of securing a large center region surrounded by the belt-shaped reinforcing member and having a very small stress. This makes it possible to arbitrarily reinforce the large opening, and when the accessory is attached to this central area, the accessory can be flexibly displaced within a limited range.
[0050]
The method for reinforcing the opening of the membrane body according to the present invention is applicable to an opening formed for a specific use purpose with respect to the membrane body, and appropriately removes a damaged portion generated in the membrane body as described in claim 3. If a smooth opening is formed by cutting and shaping into the shape shown in FIG.
[0051]
On the other hand, in the invention according to claims 4 and 5, the reinforcing member is made of a highly flexible material having the same structure as the membrane body to be reinforced, and the direction of the warp or the weft of the reinforcing member base cloth is equal to the longitudinal direction of the reinforcing member. Since the direction coincides with the direction, it is possible to form the film with high strength and a narrow width, and it is possible to follow the deformation of the film body well and to reduce the weight. In other words, this is a method for reinforcing an opening of a film body which is particularly suitable as a means for reinforcing an opening of a gas-filled hull of an airship or a gas-filled sphere of a balloon which requires flexibility and light weight.
When the reinforcing member is made of the same material as that of the film body to be reinforced, there is an advantage that the reinforced portion is unified with the film body in appearance, does not stand out, and does not impair the aesthetic appearance.
[0052]
In the invention according to claim 6, the opening angle of the right and left with respect to the center line passing substantially through the center of the opening of the reinforcing member arranged in a V shape so as to straddle the opening from the starting point is set to 30 ° or less. By reducing the centripetal force toward the center of the opening due to the stress transmitted along the reinforcing member, the increase in the stress acting on the membrane base fabric fibers in the direction orthogonal to the center line is reduced, and the deformation and wrinkles of the opening are reduced. It has the effect of suppressing the occurrence.
[0053]
In a plain weave fabric, the stress acting on the fabric is more difficult to transmit in the diagonal direction that is not along the warp and weft than in other weave fabrics. . Therefore, when the reinforcing method according to the present invention is applied to the opening formed in the film body in which the base fabric constituting the film body has a plain weave structure, the effect of the present invention is other than the above. The effect is more remarkably exhibited as compared with a membrane made of a base fabric having a woven texture.
[0054]
There is also a membrane structure in which the base fabric of the membrane body uses a membrane body structure that is not a woven fabric structure. When the base fabric constituting the membrane body is composed of two layers of fiber planes in which the warp and the weft are not entangled, the woven fabric structure is used. Tear propagation is more likely to occur than the base cloth consisting of The invention according to claim 8 applies the method for reinforcing the opening of the membrane body of the present invention to a membrane body having such a tissue structure. In such a case, the most remarkable reinforcing effect is obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a method for reinforcing a film body opening according to the present invention.
FIG. 2 is a view showing a second embodiment of the method for reinforcing the opening of the film body according to the present invention.
FIG. 3 is a view showing a third embodiment of the method for reinforcing a film body opening according to the present invention.
FIG. 4 is a view showing a fourth embodiment of the method for reinforcing a film body opening according to the present invention.
FIG. 5 is an enlarged cross-sectional view schematically showing the structure of a membrane used for a membrane structure and a reinforcing member for reinforcing the membrane opening according to the present invention.
FIG. 6 is a view schematically showing how a stress is transmitted around the opening of the film body having the opening formed therein.
FIGS. 7A and 7B are diagrams of a tensile test piece in the method of reinforcing the opening of the membrane body according to the present invention, wherein FIG. 7A shows the arrangement of the opening reinforcing member and FIG.
8A and 8B are diagrams illustrating an application example of the present invention, in which FIG. 8A illustrates an entire side surface of an airship, and FIG.
[Explanation of symbols]
1 Membrane
2 base cloth
3 resin
4 opening
5,5a Starting point
6,6a Open side
7,7a, 8,8a Reinforcing member
9,9a intersection
17, 17a, 18, 18a Reinforcing member
31, 31a Warp direction reinforcement group
32,32a Weft direction reinforcement group
37, 37a, 38, 38a reinforcing member
41, 41a Warp direction reinforcement group
42, 42a Weft direction reinforcement group
47, 47a, 48, 48a Reinforcing member

Claims (8)

In a film opening formed in a flexible film formed by coating or laminating a resin on a base fabric of a fiber woven fabric, a warp direction of a base fabric constituting the film from a substantially center position of the opening. And / or along the weft direction, points on the membrane body which are separated from each other by an appropriate distance in the opposite direction are defined as a pair of starting points, and from each starting point, along each of two straight lines passing near the outer edge of the opening. And, on the outer side opposite to the opening, strip-shaped reinforcing members having flexibility similar to the film body are arranged in a V-shape, and the respective tip sides cross each other on the opening side. And a method of reinforcing the opening of the film body by welding, bonding or sewing the reinforcing member to the film body. 2. The pair of strip-shaped reinforcing members extending from each starting point to both sides of the opening outer edge are further extended from the starting point in a direction opposite to the opening, and cross each other substantially in an X-shape on each starting point side. Method of reinforcing the membrane body opening. 2. The film body opening, which is one of an opening formed in the film body for a specific application purpose and an opening formed by cutting and shaping a damaged portion generated in the film body into an appropriate shape. 3. 3. The method for reinforcing a film body opening according to 2. The reinforcing member is formed of a flexible film body obtained by coating or laminating a resin on a base fabric of a fiber woven fabric, and is formed in a belt shape along either the warp direction or the weft direction of the base fabric constituting the film body. 4. The method of reinforcing a film body opening according to claim 1, wherein the opening is reinforced by the reinforcing member. The said reinforcement member is a member which consists of the same material as the said film body, and has a width | variety of about 70% or more of the opening width of the said opening, The said opening part is reinforced with the reinforcement member. The method of reinforcing a film body opening according to any one of the above. The point where the angle formed by a straight line passing through the vicinity of the outer edge of the opening from each of the starting points and a straight line passing through the center of the opening from the same starting point is 30 ° or less, respectively, is the starting point. The method for reinforcing a film body opening according to any one of the above. The method for reinforcing a film body opening according to any one of claims 1 to 6, wherein the fabric structure of the base fabric forming the film body is a plain weave structure. On the membrane, a warp plane formed by arranging warps in a plane at substantially equal intervals and a weft plane formed by arranging wefts in a plane at substantially equal intervals are vertically overlapped with each other so that their yarn directions cross each other. While forming the fiber plane of the layer, the upper and lower surfaces of the fiber plane of the two layers are coated with a resin or laminated with a thin resin film, and the two layers of the fiber plane are bonded and integrated and a surface protection layer is pressed by pressing the resin. The method for reinforcing a film body opening according to any one of claims 1 to 6, wherein the film body formed by performing the formation is used.

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