Waterproof structure for center seat of wing vehicle and repair method

Abstract

To provide a waterproof structure (repair method of a wing vehicle center sheet) for a wing vehicle center sheet capable of achieving a longer service life (capable of exhibiting durability and maintaining a waterproof effect for a long period).SOLUTION: There is provided a waterproof structure 1 comprising a waterproof sheet 2 for wing vehicle, the waterproof structure covers an upper part of a center sheet 105 extended so as to cover a boundary part between the center frame 101 of a load carrying platform of a wing vehicle 100 and wing roofs 102, 103. The wing vehicle waterproof sheet 2 has: an outer layer sheet 21 which is formed in a wide shape relative to a center sheet 105 and is arranged so as to straddling over the center sheet 105, and whose both side edges are fixed to top faces of the wing roofs 102, 103. An internal space 6 surrounded by the outer layer sheet 21, the outer layer sheet 105 and wing roofs 102, 103, are sealed with a sealing material 3 which has flexibility even after being cured, and the sealing material 3 is adhered to top surfaces of the wing roofs 102, 103.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a waterproof structure for a center seat that covers the opening and closing part of the cargo bed of a wing vehicle (truck), and a repair method thereof. [Background technology]

[0002] For example, as shown in Figures 4 and 5 of Patent Document 1, the loading platform (storage space) of a wing truck (a truck equipped with wing roofs that can be opened and closed on both sides of the loading platform) is structured so that a pair of wing roofs 7 are connected to both sides (left and right) of a center frame 5 that extends in the front-to-rear direction at the center of the width of the top (upper surface) and can be opened and closed (rotated) via hinges 6. In order to prevent rainwater and other liquids from entering the storage compartment through the gaps at the connecting parts (bending boundary parts) between the center frame 5 and the left and right wing roofs 7, a center sheet 8 is stretched over the center frame 5, spanning the left and right wing roofs 7. The opposite side edges of the center sheet 8 are usually fixed to the upper surface of the wing roof 7 via strip-shaped pressure plates 9 and rivets 10, and a caulking material 11 is applied to cover the upper part.

[0003] The center seat 8 is made of a flexible, waterproof sheet material, but traditionally, a sheet material (known as tarpaulin) with a base fabric impregnated with a general-purpose resin such as polyvinyl chloride has often been used. This sheet material begins to deteriorate (crack and tear) after about five years due to bending deformation caused by opening and closing the wing roof 7, as well as damage from wind, rain, ultraviolet rays, and car wash brushes, and loses its waterproofing effect, causing rain to leak into the interior of the vehicle. Therefore, in wing-type vehicles, the center seat 8 needs to be repaired periodically (approximately every five years).

[0004] There are two ways to repair a center sheet 8: replacement (removing the existing, deteriorated center sheet and replacing it with a new one) or repair (overlaying the existing, deteriorated center sheet without replacing it). However, from the standpoint of ease of construction (work time and cost), the repair method (overlaying without replacing) is becoming more common, that is, as shown in Figure 2 of Patent Document 1, in which a repair waterproof sheet 20 that is wider than the center sheet 8 is stretched over the existing center sheet 8 and stretched (overlayed) on the left and right wing roofs 7. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 3155089 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the repair waterproof sheet 20, like the center sheet 8, is required to be flexible and waterproof, but traditionally, the same sheet material (tarpaulin) as the center sheet 8 has often been used, which loses its waterproofing due to deterioration (cracks and tears) in about five years, reaching the end of its life.In addition, the caulking sections 23 applied to the edges of both sides of the repair waterproof sheet 20 also lose their waterproofing due to deterioration (cracks, thinning, peeling) in about five years, reaching the end of its life.As a result, even when the center sheet is repaired, it has been necessary to re-repair it (replacing the repair waterproof sheet) every five years or so.

[0007] Therefore, the present invention provides a waterproof structure for a center seat for a wing vehicle (a repair method for a center seat for a wing vehicle) that has a longer life (is highly durable and can maintain its waterproof effect for a long period of time). [Means for solving the problem]

[0008] The present invention provides a waterproof structure for a center seat for a wing vehicle, which includes a center sheet stretched to cover a boundary between a center frame extending in the front-rear direction at the center of the width direction of the top of the cargo bed and a wing roof rotatably connected to both sides of the center frame, and a waterproof sheet for a wing vehicle stretched to cover the center sheet, The waterproof sheet for a wing vehicle is formed to be wider than the center sheet, and includes at least a belt-shaped outer layer sheet disposed across the center sheet, with both side edges of the waterproof sheet for a wing vehicle being fixed to the upper surface of the wing roof, an internal space surrounded by the outer layer sheet, the center sheet, and the wing roof is sealed with a sealing material that remains flexible even after hardening; The sealant is adhered to at least the upper surface of the wing roof.

[0009] In the waterproof structure of conventional center seats for wing vehicles, the interior space surrounded by the outer layer sheet, center seat, and wing roof is not sealed with a sealant (adhesive). Therefore, if the outer layer sheet deteriorates (cracks or tears occur), the waterproof effect can no longer be maintained, and rainwater and other liquids can seep into the interior of the vehicle. In contrast, with the above-described configuration, the interior space is sealed (airtight) with a sealing material that remains flexible even after hardening, and the sealing material is adhered to at least the upper surface of the wing roof (for example, an aluminum metal surface). Flexible sealing materials are easily deformed and can freely deform in response to bending deformations that accompany opening and closing of the wing roof (roof opening angle: approximately 70°), eliminating the risk of cracks or other defects occurring inside. Therefore, even if the outer layer sheet deteriorates (cracks), it is possible to prevent rainwater from leaking into the cargo area. This allows for a waterproof structure for a center seat for a wing vehicle that has a longer lifespan (superior durability and the ability to maintain waterproof performance for a long period of time) than conventional structures.

[0010] In the waterproof structure for a center seat for a wing vehicle according to the present invention, the sealant may be a one-component silicone sealant that cures at room temperature.

[0011] According to the above configuration, it is possible to obtain a waterproof structure for a center sheet for a wing vehicle that is excellent in adhesiveness, durability, cold resistance, ease of installation (workability), ease of handling (environmental, hygienic, and safety aspects), and the like.

[0012] In addition, in the waterproof structure of the center seat for the above-mentioned wing vehicle, the present invention may also be such that the outer layer sheet is fixed to the upper surface of the wing roof via a strip-shaped pressure plate and rivets, without being glued or caulked at both side edges of the outer layer sheet.

[0013] In the conventional method, in which both side edges of an outer layer sheet having an adhesive layer (sticky layer) on the surface (underside) are adhered and fixed to the upper surface of the wing roof, air bubbles and wrinkles are likely to occur during the fixing process (especially in strong winds), and correcting these is not easy, which may impair workability during installation. Furthermore, although the outer layer sheet does not have an adhesive layer (sticky layer) on the surface (underside) of both side edges, if caulking is to be applied to both side edges, it is necessary to first fix both side edges to the upper surface of the wing roof using strip-shaped pressure plates and rivets. In contrast, in the above-mentioned configuration, the internal space surrounded by the outer layer sheet, center sheet, and wing roof is sealed with a sealant, and the sealant is adhered to at least the upper surface of the wing roof (for example, the aluminum metal surface), so that the waterproofing effect is maintained even if both side edges of the outer layer sheet are partially peeled off from the wing roof. Therefore, there is no need to take the trouble of gluing or caulking both side edges of the outer layer sheet, as in the past, and there is no decrease in workability (workability) in order to ensure waterproofing.

[0014] In addition, in the waterproof structure for the center seat for a wing vehicle of the present invention, the waterproof sheet for a wing vehicle may further include a strip-shaped inner layer sheet that covers the center seat within the internal space.

[0015] According to the above configuration, the reliability of the waterproof effect of the waterproof structure of the center seat for a wing vehicle can be further improved.

[0016] The present invention also provides a waterproof sheet for a wing vehicle used in the waterproof structure of the center seat for a wing vehicle, comprising: The outer layer sheet may have a waterproof layer made of vulcanized rubber or synthetic resin, with a base fabric embedded or laminated therein as a reinforcing material.

[0017] Compared to conventional waterproof sheets (tarpaulins) that contain a base fabric but are relatively thin (even thick ones have a total thickness of around 0.5 mm) and have a base fabric impregnated with a general-purpose resin such as polyvinyl chloride, this waterproof sheet uses a waterproof layer made of vulcanized rubber or synthetic resin with a base fabric embedded or laminated as a reinforcing material in the outer layer, which allows the waterproof layer to be made sufficiently thick, thereby suppressing deterioration of the sheet material and maintaining the waterproof effect for a longer period of time. Furthermore, even if minor scratches occur on the surface of the sheet due to contact with tree branches while driving or the brushes of a car wash, the waterproof layer is relatively thick and can prevent the base fabric from being cut (and therefore the waterproof sheet from tearing), further improving the damage resistance (resistance to external damage, etc.) of the waterproof sheet for wing vehicles. Furthermore, even if the base fabric is partially torn (shock tear) due to an external impact, the waterproof layer, which has a higher elongation rate than the base fabric, is easily deformed and less likely to break, so the waterproof effect can be maintained for a longer period of time.

[0018] Further, the present invention provides the center seat for a wing vehicle, The waterproof layer of the outer layer sheet may be formed from vulcanized rubber, and the rubber component may contain ethylene-propylene-diene terpolymer (EPDM).

[0019] According to the above configuration, the waterproof layer has superior weather resistance and is less susceptible to deterioration (cracking) due to wind, rain, ultraviolet rays, etc., compared to when the waterproof layer is made of a general-purpose synthetic resin such as polyvinyl chloride, so the waterproof effect can be maintained for an even longer period of time.

[0020] The present invention also provides a method for repairing a center seat for a wing vehicle, using a waterproof sheet for a wing vehicle stretched over the center sheet stretched over the boundary between a center frame extending in the front-rear direction at the center of the width of the top of the cargo bed and a wing roof rotatably connected to both sides of the center frame, the method comprising: a step of disposing, as the waterproof sheet for the wing vehicle, at least a strip-shaped outer layer sheet formed wider than the center sheet in a state of straddling the center sheet, and fixing both side edge portions of the outer layer sheet to the upper surface of the wing roof; The method includes a step of sealing the interior space surrounded by the outer layer sheet, the center sheet, and the wing roof with a sealant that remains flexible even after hardening, and adhering the sealant to at least the upper surface of the wing roof.

[0021] In conventional methods for repairing center seats for wing vehicles, the interior space surrounded by the outer layer sheet, center seat, and wing roof is not sealed with a sealant (adhesive). Therefore, if the outer layer sheet deteriorates (cracks or tears occur), the waterproofing effect can no longer be maintained, and rainwater and other liquids can seep into the interior of the vehicle. In contrast, in this method, the interior space is sealed with a sealant that remains flexible even after hardening, and the sealant is bonded to at least the upper surface of the wing roof (e.g., an aluminum metal surface). The flexible sealant is easily deformed and can freely deform in response to the bending deformation that occurs when the wing roof is opened and closed (roof opening angle: approximately 70°), eliminating the risk of cracks or other defects occurring inside. Therefore, even if the outer layer sheet deteriorates (cracks), it is possible to prevent rainwater from leaking into the cargo area. This means that the center seat for a wing vehicle can be repaired with a longer lifespan than conventional center seats (it is highly durable and can maintain its waterproof effect for a long period of time). [Effects of the Invention]

[0022] It is possible to provide a waterproof structure for a center seat for a wing vehicle (a repair method for a center seat for a wing vehicle) that has a longer life (is highly durable and can maintain its waterproof effect for a long period of time). [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is an explanatory diagram of a wing vehicle. [Figure 2] 1 is a cross-sectional view in the width direction of a waterproof structure for a wing vehicle according to a first embodiment. [Figure 3] FIG. 10 is a cross-sectional view in the width direction of the waterproof structure for a wing vehicle according to a second embodiment. [Figure 4] 1 is an explanatory diagram of the waterproof structure of the outer layer sheet at the front and rear ends of the cargo bed of a wing vehicle. [Figure 5] 1 is an explanatory diagram of the waterproof structure of the outer layer sheet at the front and rear ends of the cargo bed of a wing vehicle. [Figure 6] FIG. 2 is an explanatory diagram of an example of a laminated structure of an outer layer sheet. [Figure 7] FIG. 2 is an explanatory diagram of an example of a laminated structure of an outer layer sheet. [Figure 8] 10 is an explanatory diagram of a waterproof structure relating to a modified outer layer sheet at the front and rear ends of the cargo bed of a wing vehicle. FIG. [Figure 9]9 is a cross-sectional view of the waterproof structure according to the modified example of FIG. 8 taken along the line A-B. [Figure 10] FIG. 10 is an explanatory diagram of a test pattern in a bench bending durability test according to an example. DETAILED DESCRIPTION OF THE INVENTION

[0024] (Embodiment 1) A waterproof structure 1 for covering the opening and closing portion of the bed of a wing vehicle 100 (truck) and a repair method therefor will be described.

[0025] (100 wing vehicles) As shown in Figure 1, before repair using the waterproof structure 1 of this embodiment, the wing vehicle 100 has a pair of aluminum wing roofs 102 and 103 connected to both sides (left and right) of a center frame 101 (see Figure 2) that extends in the front-to-rear direction at the center of the width of the top (upper surface) of the cargo bed, and which can be opened and closed (rotated freely) via hinges 104 (see Figure 2).

[0026] In order to prevent rainwater and the like from entering the interior of the loading platform through the gaps at the connecting parts between the center frame 101 and the wing roof 102 and the gaps at the connecting parts between the center frame 101 and the wing roof 103, a center sheet 105 is already installed covering the center frame 101 and straddling the wing roofs 102 and 103 on both sides of it. Both side edges of the center sheet 105 are fixed to the upper surfaces of the wing roofs 102 and 103 via plate-shaped pressure plates 106 and rivets 107, and the tops of these are covered with a coating of caulking material 108.

[0027] (Waterproof structure 1) As shown in FIG. 2, the waterproof structure 1 of this embodiment is configured in such a manner that a waterproof sheet 2 for a wing vehicle is further stretched on top of an existing center sheet 105 of a wing vehicle 100. Specifically, the waterproof sheet 2 for wing vehicles is arranged across the center sheet 105 and includes at least an outer layer sheet 21 whose both side edges are fixed to the upper surface of the wing roofs 102 and 103, and the internal space 6 surrounded by the outer layer sheet 21, center sheet 105, and wing roofs 102 and 103 is sealed with a sealing material 3 that remains flexible even after hardening.

[0028] (Waterproof sheet for wing vehicles 2) The waterproof sheet 2 for a wing vehicle has as its main component a strip-shaped outer layer sheet 21. The outer layer sheet 21 is formed to be wider (in the width direction) than the center sheet 105, and is disposed so as to straddle the center sheet 105. Both side edge portions (in the width direction) of the outer layer sheet 21 are fixed to the upper surfaces of the wing roofs 102 and 103 via rivets 5 while being pressed by strip-shaped pressure plates 4.

[0029] The waterproof sheet 2 for wing vehicles is configured to satisfy waterproofness, flexibility, weather resistance, damage resistance, ease of handling, etc. The outer layer sheet 21 constituting the waterproof sheet 2 for wing vehicles may be, for example, a waterproof sheet in which a base fabric 243 serving as a reinforcing material is embedded or laminated between waterproof layers 241 and 242 made of vulcanized rubber or synthetic resin, as shown in Fig. 6, or a waterproof sheet in which a waterproof layer 241 and a base fabric 243 made of vulcanized rubber or synthetic resin are laminated together, as shown in Fig. 7.

[0030] The thickness (total thickness) of the outer layer sheet 21 is, for example, 0.7 to 2.5 mm, preferably 0.8 to 2 mm, more preferably 0.9 to 1.5 mm, and most preferably 1.0 to 1.2 mm (particularly 1.1 mm), which is significantly thicker than tarpaulin (even thicker ones have a total thickness of around 0.5 mm). If the thickness is less than 0.7 mm, waterproofness and resistance to external damage may be impaired. On the other hand, if the thickness exceeds 2.5 mm, it becomes difficult to ensure flexibility. In particular, when the outer layer sheet 21 is formed by joining sheets, the step becomes large at the joint, which is undesirable because it impairs flexibility and appearance.

[0031] The outer layer sheet 21 is formed to be wider (for example, about 600 mm wide) than the existing center sheet 105 (for example, about 350 to 400 mm wide). For example, the length of the outer layer sheet 21 in the front-to-rear direction is about 7 m for a 4-ton vehicle and about 11 m for a 10-ton vehicle.

[0032] Examples of vulcanized rubber or synthetic resins constituting the waterproof layers 241 and 242 of the outer sheet 21 include vulcanized rubbers such as EPDM (ethylene-propylene-diene terpolymer), IIR (butyl rubber), NR (natural rubber), SBR (styrene-butadiene rubber), CR (chloroprene rubber), NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber), and CSM (chlorosulfonated polyethylene), as well as synthetic resins such as thermoplastic elastomers, polyethylene, polypropylene, and polyvinyl chloride. When the waterproof layer is formed of vulcanized rubber, these rubber components can be used alone or in combination. Among these rubber components, EPDM (ethylene-propylene-diene terpolymer) alone or a blend of EPDM (ethylene-propylene-diene terpolymer) and IIR (butyl rubber) is preferred because of its excellent weather resistance, resistance to deterioration (cracking) due to wind, rain, ultraviolet rays, etc., and ability to maintain waterproofing for a longer period of time. A blend of EPDN (ethylene-propylene-diene terpolymer) and IIR (butyl rubber) is preferred because it also has excellent extensibility.

[0033] The base fabric 243 (fibrous structure) that is the reinforcing material of the outer layer sheet 21 can be selected from various known structures such as woven fabric, knitted fabric, nonwoven fabric, woven blind fabric, net (network structure or mesh), etc. Among these, woven fabrics such as plain weave, twill weave, and satin weave are preferred from the viewpoints of excellent mechanical properties and economy.

[0034] Examples of fibers constituting the base fabric 243 (fiber structure) include synthetic fibers such as polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), polyamide fibers (polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), polyester fibers (polyalkylene arylate fibers, etc.), vinyl alcohol fibers (polyvinyl alcohol fibers, ethylene-vinyl alcohol copolymer fibers, vinylon fibers, etc.), and polyparaphenylene benzobisoxazole (PBO) fibers; cellulose fibers (cellulose fibers such as cotton fibers, cellulose derivative fibers, etc.); natural fibers such as wool; and inorganic fibers such as carbon fibers. These fibers may be used alone as a single yarn, or may be combined to form a composite yarn (blended yarn, etc.) of two or more types.

[0035] Among these fibers, polyester fibers are preferred because of their excellent mechanical properties and economical efficiency. The polyester fibers may be polyalkylene arylate fibers. Examples of polyalkylene arylate fibers include poly(C) fibers such as polyethylene terephthalate (PET) fibers and polyethylene naphthalate (PEN) fibers. 2-4 Alkylene-C 8-14 arylate fibers, etc. These polyester fibers may be used alone or in combination of two or more.

[0036] Furthermore, the base fabric 243 may be configured to have excellent extensibility so that the waterproof sheet 2 for wing-type vehicles has excellent extensibility. For example, it may be a fabric woven from thermoplastic fiber filaments with excellent extensibility, a fabric using urethane elastic yarn or woolen yarn, or a fabric in which the base fabric has a core yarn made of polyester-based low-oriented yarn or polyamide-based unstretched yarn, and the warp and weft yarns are obtained by wrapping a covering yarn around this core yarn (see Figures 3 and 4 of Japanese Patent No. 2854771). When the base fabric 243 has such a configuration, the resulting waterproof sheet 2 for wing-type vehicles has excellent extensibility, which allows the internal sealant 3 to deform more freely when the wing roofs 102, 103 are opened and closed, thereby more effectively suppressing deterioration of the sealant 3 and the like.

[0037] The thread density (arrangement density of warp and weft threads) of the base fabric 243 is set appropriately from the viewpoint of achieving both suppleness (flexibility) and reinforcement (resistance to external damage) of the entire waterproof sheet 2 for a wing-type vehicle. The position of the base fabric 243 is not particularly limited from the viewpoint of reinforcing the wing vehicle waterproof sheet 2, and it may be embedded between the two upper and lower waterproof layers 241 and 242 (Fig. 6), embedded within a single waterproof layer, or laminated on one side of the single waterproof layer 241 (Fig. 7). Of these, it is preferable to embed the base fabric 243 between the two upper and lower waterproof layers 241 and 242 in view of excellent resistance to external damage, ease of handling (abrasion resistance), and productivity.

[0038] The outer layer sheet 21 may be a single layer, or may be multi-layered (for example, 2 to 3 layers) within the range that allows flexibility, etc., but a single layer (1 ply) is preferred from the standpoints of workability and economy.

[0039] Compared to conventional waterproof sheets (tarpaulins) that contain a base fabric but are relatively thin (even thick ones have a total thickness of around 0.5 mm) and have a base fabric impregnated with a general-purpose resin such as polyvinyl chloride, this embodiment uses an outer layer sheet 21 made of vulcanized rubber or synthetic resin, in which a base fabric 243 is embedded or laminated between waterproof layers 241 and 242 as a reinforcing material, or an outer layer sheet 21 in which waterproof layer 241 and base fabric 243 are laminated together.This allows the waterproof layers 241 and 242 to be made sufficiently thick, which suppresses deterioration of the sheet material and enables the waterproof effect to be maintained for a longer period of time. Furthermore, even if minor scratches are made on the surface of the sheet due to contact with tree branches while driving or the brushes of a car wash machine, the waterproof layer 241 is relatively thick and can prevent the base fabric 243 from being cut (and thus the outer layer sheet 21 from being torn), thereby further improving the damage resistance (resistance to external damage, etc.) of the waterproof sheet for wing vehicles 2. Furthermore, even if the waterproof sheet 2 is subjected to an external impact and only the base fabric 243 is partially cut (shock tear), the waterproof layers 241 and 242, which have a higher elongation rate than the base fabric 243, are easily deformed and less likely to break, so the waterproof effect can be maintained for a longer period of time.

[0040] (Sealant 3) As shown in Figure 2, the interior space 6 surrounded by the outer sheet 21, center sheet 105, and wing roofs 102 and 103 is sealed with a sealant 3 (adhesive) that remains flexible even after hardening, and this sealant 3 is adhered to the upper surfaces (aluminum metal surfaces) of the wing roofs 102 and 103. This eliminates the need to bother with gluing or caulking the side edges of the outer sheet 21, and ensures that rainwater and other contaminants are prevented from entering the interior space 6 even if the side edges of the outer sheet 21 are partially peeled off from the wing roofs 102 and 103.

[0041] Examples of the sealant 3 include solvent-based adhesives, water-based adhesives, and solventless sealants (adhesives) that harden through chemical reactions. Among these, solventless sealants (adhesives) that harden through chemical reactions are preferred due to their ease of handling (environmental, hygienic, and safety aspects) and ease of application (workability). As solventless sealants (adhesives) that harden through chemical reactions, polyurethane-based sealants and silicone-based sealants are preferred due to their flexibility even after hardening. Silicone-based sealants are particularly preferred due to their excellent adhesive strength between different materials such as rubber, plastic, and metal. As silicone-based sealants, one-component silicone-based sealants that harden at room temperature are particularly preferred due to their excellent adhesion, durability, cold resistance, and ease of application (shaping workability).

[0042] In addition, in order to improve the adhesion between the sealant 3 and the wing roofs 102 and 103, the surfaces (for example, aluminum metal surfaces) of the wing roofs 102 and 103 to be coated with the sealant 3 may be pretreated with a primer.

[0043] As for the waterproof structure 1 for the center sheet 105, as long as the sealant 3 is bonded to the upper surfaces of the wing roofs 102 and 103, the outer layer sheet 21 and the sealant 3, and the existing center sheet 105 (and the caulking material 108 on both side edges) and the sealant 3 do not necessarily need to be bonded together, but rather they need only be in close contact.

[0044] Furthermore, the sealant 3 according to this embodiment is a paste (semi-solid) before hardening (during application), is easy to shape during application, and remains soft and rubbery after application, providing excellent flexibility. The hardness of the sealant after hardening (after application) may be, for example, 10 to 40, preferably 15 to 35, as measured using a Type A durometer according to a hardness test method specified in JIS K6253 (2012). If the hardness of the sealant 3 (after hardening) is too low, the viscosity of the sealant before hardening (during application) may be too low, which may impair application (shaping workability). If the hardness is too high, flexibility may not be ensured, which may result in internal cracks or other defects, resulting in reduced waterproofing.

[0045] As described above, since the sealing material 3 is tightly packed in the internal space 6 in an undegraded state, it is possible to prevent rainwater and the like from entering the interior of the loading platform even if the outer layer sheet 21 is damaged by external injury or the like. Furthermore, since the outer layer sheet 21 and the sealing material 3 are not firmly bonded together, the outer layer sheet 21 can be relatively easily peeled off at the contact interface with the sealing material 3 without damaging the sealant 3, making it possible to replace only the outer layer sheet 21 with a new one.

[0046] The term "sealant" is used for convenience with the intention of "gap filling," and does not exclude what are generally called adhesives, paints, molding materials, coating materials, etc.

[0047] In the waterproof structure of conventional center seats for wing vehicles, the interior space surrounded by the outer layer sheet, center seat, and wing roof is not sealed with a sealant (adhesive). Therefore, if the outer layer sheet deteriorates (cracks or tears occur), the waterproof effect can no longer be maintained, and rainwater and other liquids can seep into the interior of the vehicle. In contrast, in this embodiment, the interior space 6 is sealed (airtight) with a sealant 3 that remains flexible even after hardening, and the sealant 3 is adhered to at least the upper surfaces of the wing roofs 102 and 103. The flexible sealant 3 is easily deformable and can freely deform in response to bending deformations that occur when the wing roofs 102 and 103 are opened and closed (roof opening angle: approximately 70°), eliminating the risk of cracks or other defects occurring inside. Therefore, even if the outer layer sheet 21 deteriorates (cracks), rainwater leakage into the cargo area can be prevented. This allows for a waterproof structure 1 with a longer lifespan (superior durability and the ability to maintain waterproof performance for a long period of time) than conventional structures.

[0048] (Pressure plate 4 and rivet 5) The pressure plate 4 in this embodiment is made of aluminum and has an L-shaped cross section along the width direction, with a single-flange-shaped pressure member 41 extending toward the center in the width direction. The pressure plate 4 is also formed so that, when placed on the upper surfaces of the wing roofs 102 and 103, the size of the gap (dimension in the plate thickness direction) between the pressure member 41 and the wing roofs 102 and 103 is slightly smaller than the thickness of the outer sheet 21. This ensures that both side edges of the outer sheet 21 are securely fixed to the upper surfaces of the wing roofs 102 and 103 via the rivets 5, sandwiched between the undersides of the pressure members 41 and the upper surfaces of the wing roofs 102 and 103 while being compressed in the sheet thickness direction. This prevents partial peeling of the outer sheet 21.

[0049] In this embodiment, as described above, both side edges of the outer layer sheet 21 are fixed to the upper surfaces of the wing roofs 102 and 103 via strip-shaped pressure plates 4 and rivets 5 without being glued or caulked. In the conventional method, in which both side edges of an outer layer sheet having an adhesive layer (sticky layer) on the surface (underside) are adhered and fixed to the upper surface of the wing roof, air bubbles and wrinkles are likely to occur during the fixing process (especially in strong winds), and correcting these is not easy, which may impair workability during installation. Furthermore, although the outer layer sheet does not have an adhesive layer (sticky layer) on the surface (underside) of both side edges, if caulking is to be applied to both side edges, it is necessary to first fix both side edges to the upper surface of the wing roof using strip-shaped pressure plates and rivets. In contrast, in this embodiment, the interior space 6 surrounded by the outer layer sheet 21, center sheet 105, and wing roofs 102 and 103 is sealed with the sealant 3, and the sealant 3 is adhered to at least the upper surfaces (aluminum metal surfaces) of the wing roofs 102 and 103, so the waterproofing effect is maintained even if both side edge portions of the outer layer sheet 21 are partially peeled off from the wing roofs 102 and 103. Therefore, there is no need to take the trouble of gluing or caulking both side edge portions of the outer layer sheet 21, as in the past, and there is no decrease in workability (ease of installation) in order to ensure waterproofing.

[0050] (Waterproof structure 1 of outer layer sheet 21 at front and rear ends of cargo bed) As for the waterproof structure 1 of the outer layer sheet 21 at the front and rear ends of the cargo bed, for example, as shown in Figures 4 and 5, at the front end of the cargo bed, the front and rear end (front end) of the existing center sheet 105 is removed in advance, and the front and rear end (front end) of the outer layer sheet 21 is extended and folded so as to cover the upper part of the front wall of the cargo bed and the upper part of the front end surface of the wing roofs 102 and 103 (Figure 4(a)), and slits 212 and 213 are formed at a predetermined interval in two places approximately in the center of this extended folded portion 211, thereby dividing this extended folded portion 211 into three compartments consisting of a left cut piece 211A, a central cut piece 211B, and a right cut piece 211C (Figure 4(b)).

[0051] The central notch 211B of the extending bent portion 211 is fixed to the upper center in the width direction of the front wall of the cargo bed via rivets 214 and 215 (FIG. 5(c)), the left notch 211A of the extending bent portion 211 is fixed to the upper front end surface of the wing roof 102 via a flat backing plate 216 and rivets 217 and 218, and the right notch 211C of the extending bent portion 211 is fixed to the upper front end surface of the wing roof 103 via a flat backing plate 219 and rivets 220 and 221 (FIG. 5(d)). The backing plates 216 and 219 are a pair on the left and right, and are arranged so that they are substantially butted together when the wing roofs 102 and 103 are closed, so that they do not come into contact with each other when the wing roofs 102 and 103 are opened or closed. In other words, when the wing roofs 102 and 103 are closed, as viewed in the fore-and-aft direction of the cargo bed, the portions 216A and 219A of the support plates 216 and 219 near the widthwise center of the cargo bed and the central cut-out piece 211B of the extended folded portion 211 of the outer layer sheet 21 are securely overlapped, thereby more reliably preventing rainwater and the like from entering the cargo bed's interior from the front end side when the cargo bed is being driven, etc. The waterproof structure 1 of the outer layer sheet 21 at the rear end of the cargo bed is also substantially the same as that at the front end of the cargo bed.

[0052] (Waterproof structure 1' according to a modified example of the waterproof structure 1 for the outer layer sheet 21 at the front and rear ends of the cargo bed) As an example of a waterproof structure 1' relating to a modified example of the waterproof structure 1 for the outer layer sheet 21 at the front and rear ends of the cargo bed, for example, at the front end of the cargo bed shown in Figures 4 and 5, without removing the front-to-rear end (front end) of the existing center sheet 105, the front-to-rear end (front end) of the outer layer sheet 21 is extended and folded so as to cover the upper part of the front wall of the cargo bed and the upper part of the front end surface of the wing roofs 102 and 103 (Figure 4(a)), and slits 212 and 213 are formed at two locations approximately in the center of this extended folded portion 211 at a predetermined interval, thereby dividing this extended folded portion 211 into three compartments consisting of a left cut piece 211A, a central cut piece 211B, and a right cut piece 211C (Figure 4(b)). In addition, in this waterproof structure 1', a rustproof claw metal fitting 231 with a concave cross section is fixed to the tip of the central cutout piece 211B via rivets 232 and 233, as shown in FIG.

[0053] The central notch 211B of the extending bent portion 211 is fixed to the upper center of the width direction of the front wall of the cargo bed in such a manner that the hook 231 attached to the tip of the central notch 211 is inserted (hooked) into the gap between the front wall (upper center of the width direction) and the existing center sheet 105 (front end), which has been previously fixed to the upper center of the width direction of the front wall of the cargo bed via a flat backing plate 241 and rivets 242 and 243 (FIG. 9). In other words, unlike the waterproof structure 1, without taking the trouble of fixing the central notch 211B of the extending bent portion 211 to the upper center of the width direction of the front wall of the cargo bed via rivets 214 and 215, the central notch 211B is fixed to the upper center of the width direction of the front wall of the cargo bed by inserting and hooking the hook 231 between the existing center sheet 105 (front end) and the front wall (upper center of the width direction). This makes it easier to arrange the strip-shaped outer layer sheet 21 from the front wall of the loading platform to the top of the loading platform and the rear wall of the loading platform, straddling the existing center sheet 105 without slack.

[0054] The left notch 211A of the extending bent portion 211 and the right notch 211C of the extending bent portion 211 may be fixed to the upper front end surfaces of the wing roofs 102 and 103 via flat pressure plates and rivets, respectively, similar to the waterproof structure 1 of the outer layer sheet 21 at the front and rear ends of the cargo bed, or may be fixed to the upper front end surfaces of the wing roofs 102 and 103 by being clamped using clip fittings with strong gripping power (not shown). The waterproof structure 1' of the outer layer sheet 21 at the rear end of the cargo bed is also substantially the same as that at the front end of the cargo bed.

[0055] (Embodiment 2) 3, in the waterproof structure 201 of the second embodiment, the waterproof sheet 2 for a wing vehicle is configured to include not only an outer layer sheet 21 but also a strip-shaped inner layer sheet 22 that covers the center sheet 105 below the outer layer sheet 21 (inside the internal space 6). The other configurations are the same as those of the first embodiment.

[0056] The inner layer sheet 22 may be a waterproof sheet containing a base fabric 243 similar to that of the outer layer sheet 21, but from the viewpoint that weather resistance and external damage resistance are not particularly required, it may be a sheet material containing only a waterproof layer 241 made of vulcanized rubber or synthetic resin, or it may be tarpaulin similar to the existing center sheet 105. Of these, from the viewpoint of preventing confusion between the inner layer sheet 22 and the outer layer sheet 21, it is preferable to use a waterproof sheet containing a base fabric 243, which is common to the outer layer sheet 21, and from the viewpoint of excellent economy, it is preferable to use a sheet material containing only the waterproof layer 241 (without a base fabric) or tarpaulin.

[0057] From the viewpoint of ensuring flexibility, it is preferable that the inner layer sheet 22 be stretched between the outer layer sheet 21 and the center sheet 105 via a sealant 3 (adhesive) that remains flexible even after hardening, with both side edges in contact with the caulking material 108 applied to both side edges of the center sheet 105 or the upper surface of the pressure plate 106, and with the inner layer sheet 22 and the center sheet 105 not in direct contact with each other (their deformed portions). In this case, the waterproof structure 201 has a structure in which the outer layer sheet 21 and the inner layer sheet 22 are sealed with the sealant 3, and the inner layer sheet 22 and the center sheet 105 are also sealed with the sealant 3.

[0058] Also, in the waterproof structure 201, as long as the sealant 3 is bonded to the upper surfaces of the wing roofs 102 and 103, the outer layer sheet 21 and the sealant 3, the inner layer sheet 22 and the sealant 3, and the existing center sheet 105 (and the caulking material 108 on both side edges) and the sealant 3 do not necessarily need to be bonded together, as long as they are in close contact.

[0059] Furthermore, the inner layer sheet 22 may be formed slightly shorter than the center sheet 105 in the width direction due to its structure (see FIG. 3).

[0060] As in the above-mentioned embodiment 2, the waterproof sheet 2 for a wing vehicle can be configured to further include a strip-shaped inner layer sheet 22 that covers the center seat 105 within the internal space 6, thereby further increasing the reliability of the waterproof effect of the waterproof structure 201.

[0061] (Installation procedure for waterproof sheet 2 for wing vehicles (repair method for waterproof sheet for wing vehicles)) The procedure for installing the waterproof sheet 2 for a wing vehicle (procedure for repairing the center sheet 105) will be described below using the waterproof structure 201 of the second embodiment having the inner layer sheet 22 as an example.

[0062] First, the sealant 3 (paste-like) for sealing the interior space 6 surrounded by the outer layer sheet 21, center sheet 105, and wing roofs 102 and 103 is spread over the entire upper part of the center sheet 105 (the recessed part between both side edges) without leaving any gaps, until it is flush with the caulking material 108 applied to both side edges of the center sheet 105 or the top surface of the retaining plate 106. At this time, patches (vinyl tape) are applied in advance to cover areas of the center sheet 105 that are relatively badly damaged (holes, tears).

[0063] Next, the inner layer sheet 22 is stretched on top of the sealant 3 that has been spread over the center sheet 105 .

[0064] Furthermore, sealant 3 (paste-like) for sealing the interior space 6 is spread over the top of the inner layer sheet 22, the top of both side edges of the center sheet 105 (caulking material 108 or retaining plate 106), and the entire upper surface of the wing roofs 102 and 103 between both side edges of the center sheet 105 and both side edges of the outer layer sheet 21, to a thickness that does not cause any bald spots or depressions (a thickness that ensures that the interior space 6 below the outer layer sheet 21 is sealed without gaps with sealant 3 when the outer layer sheet 21 is installed: approximately 2 to 3 mm). At this time, it is preferable to pretreat the upper surface portions of the wing roofs 102 and 103 (aluminum metal) that will be covered with sealant 3 in advance with a predetermined primer.

[0065] Next, the outer layer sheet 21 is stretched over the sealant 3 spread on top of the inner layer sheet 22, and both side edges are fixed to the upper surfaces of the wing roofs 102 and 103 via pressure plates 4 and rivets 5. At this time, the outer layer sheet 21 is stretched in the front-to-rear direction while lightly pressing the widthwise center of the outer layer sheet 21 against the layer of sealant 3 to prevent air from getting trapped between the outer layer sheet 21 and the sealant 3 and to the extent that wrinkles do not form in the widthwise center of the outer layer sheet 21. It is also preferable to stretch the outer layer sheet 21 in the width direction while lightly pressing the widthwise center toward both side edges against the layer of sealant 3 to the extent that wrinkles do not form in the entire outer layer sheet 21.

[0066] Finally, the front and rear ends of the outer sheet 21 are waterproofed (waterproofed at the front and rear ends of the cargo bed) in the manner described above (see the section "Waterproof structure 1 for the outer sheet 21 at the front and rear ends of the cargo bed").

[0067] In addition, the installation procedure for the waterproof sheet 2 for a wing vehicle in the waterproof structure 1 without the inner layer sheet 22 of embodiment 1 is carried out by omitting the process of applying the sealing material 3 between the center sheet 105 and the inner layer sheet 22 and the process of stretching the inner layer sheet 22 from the installation procedure for the waterproof sheet 2 for a wing vehicle in embodiment 2 above.

[0068] Furthermore, in the above-described first and second embodiments, it is assumed that when the existing center sheet 105 deteriorates, the waterproof sheet 2 for a wing vehicle is stretched over the existing center sheet 105 without replacing the center sheet 105, but the use of the waterproof sheet 2 for a wing vehicle is not limited to the above-described case. For example, the waterproof sheet 2 for a wing vehicle can also be stretched over a new center sheet 105 of a cargo bed in order to prevent deterioration of the new center sheet 105.

[0069] The above repair method involves placing a strip-shaped outer layer sheet 21, which is wider than the center sheet 105 and serves as a waterproof sheet 2 for wing vehicles, straddling the center sheet 105, and fixing both side edges of the outer layer sheet 21 to the upper surface of the wing roofs 102 and 103, and also sealing the internal space 6 with a sealant 3 and adhering the sealant 3 to the upper surface of the wing roofs 102 and 103. In conventional methods for repairing center seats for wing vehicles, the interior space surrounded by the outer layer sheet, center seat, and wing roof is not sealed with a sealant (adhesive). Therefore, if the outer layer sheet deteriorates (cracks or tears occur), the waterproofing effect can no longer be maintained, and rainwater and other liquids can seep into the interior of the vehicle. In contrast, in the repair method described above, the interior space 6 is sealed (closed) with a sealant 3 that remains flexible even after hardening, and the sealant 3 is bonded to at least the upper surface (aluminum metal surface) of the wing roofs 102 and 103. The flexible sealant 3 is easily deformed and can freely deform in response to bending deformations associated with opening and closing the wing roofs 102 and 103 (roof opening angle: approximately 70°), eliminating the risk of cracks or other defects occurring inside. Therefore, even if the outer layer sheet 21 deteriorates (cracks), rainwater leakage into the cargo area can be prevented. This allows repairs to be made to the waterproof structure 1 or waterproof structure 201, which has a longer lifespan (superior durability and can maintain waterproofing for a long period of time) than conventional structures. [Example]

[0070] In the present invention, the waterproof structure of the center seat for a wing vehicle (hereinafter referred to as the waterproof structure), which seals (hermetically seals) the internal space surrounded by the outer layer sheet, the center seat, and the wing roof, must be both flexible and waterproof even when subjected to bending deformation caused by opening and closing the wing roof. Therefore, in this example, waterproof structures according to Examples 1 to 10 and Comparative Examples 1 and 2 (hereinafter referred to as "test specimens") were fabricated and subjected to a drop impact test (evaluation of external damage resistance), a sunshine weather resistance test (evaluation of weather resistance), a bench bending durability test (evaluation of bending durability), and a high-pressure water spray test (evaluation of waterproofness), and comparative verification was performed. The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Details of each component material (waterproof sheet, sealant, etc.) used in the examples, their production methods, and methods for measuring or evaluating each physical property are shown below.

[0071] [Materials used] [Tarp] (Outer layer sheet) Outer layer sheets W1 to W5 shown in Table 1 were prepared as outer layer sheets to be used as waterproof sheets for each test specimen.

[0072] [Table 1]

[0073] As the outer layer sheet of W1, a fiber-reinforced vulcanized rubber (EPDM) waterproof sheet (product name: "Mizusheet (registered trademark) KS") manufactured by Mitsuboshi Belting Co., Ltd. was used. The outer layer sheet of W1 was produced by the following procedure. First, the rubber composition of composition C1 shown in Table 2 (EPDM used as the rubber component) was kneaded in a Banbury mixer, and this kneaded rubber was passed through a calendar roll to form a rolled rubber sheet of a specified thickness, and two sheets (two rolls) of unvulcanized rubber sheets for the waterproof layer of the outer layer sheet were produced. In order to facilitate a balance between suppleness (flexibility) and reinforcement (resistance to external damage), a plain weave base fabric (Fabric A) (thickness 0.3 mm) composed of warp yarns (arrangement density: 30 yarns / 5 cm) of polyethylene terephthalate (PET) with a total fineness of 250 dtex and weft yarns (arrangement density: 15 yarns / 5 cm) of polyethylene terephthalate (PET) with a total fineness of 550 dtex was placed between the two unvulcanized rubber sheets, and the components were pressed together through a pair of rolls to form a 1.1 mm thick outer layer sheet precursor (laminate). Next, this outer layer sheet precursor was sandwiched between conveyors and moved at a speed of about 1.5 m / min, while being introduced into a long, narrow continuous vulcanizing device whose internal space was adjusted to a temperature of 170 to 180°C and a pressure of 0.2 MPa. As the outer layer sheet precursor moved through the vulcanizing device, an outer layer sheet (total thickness 1.1 mm) was obtained in which the base fabric was embedded in the vulcanized waterproof layer (vulcanized rubber layer).

[0074] The outer layer sheet of W2 was prepared in the same manner as the outer layer sheet of W1, except that in preparing the outer layer sheet precursor, one unvulcanized waterproof layer rubber sheet (composition C1) was layered on a plain weave (fabric A) base fabric (thickness 0.3 mm), and the layers were passed through a pair of rolls to press the components together and form an outer layer sheet precursor (laminate) with a thickness of 0.7 mm. An outer layer sheet (total thickness 0.7 mm) was prepared by laminating a vulcanized waterproof layer (vulcanized rubber layer) and a base fabric.

[0075] The outer layer sheet of W3 was produced by the following procedure: Both sides of the base fabric (thickness 0.3 mm) of Fabric A were coated with a polyvinyl chloride resin paste (product name: Paste PVC, manufactured by Kaneka Corporation) to a thickness of 0.2 mm using a knife coater, to obtain an outer layer sheet (total thickness 0.7 mm) in which the base fabric was embedded in a waterproof layer (resin layer).

[0076] The outer layer sheet of W4 was a vulcanized rubber (EPDM) waterproof sheet (product name: "Neo Roofing E") manufactured by Mitsuboshi Belting Co., Ltd. The outer layer sheet of W4 was produced in the same manner as the outer layer sheet of W1, except that a 1.1 mm thick single-layer rolled rubber sheet (composition C1) was molded as the outer layer sheet precursor, resulting in an outer layer sheet (1.1 mm thick) consisting of only a vulcanized waterproof layer (vulcanized rubber layer).

[0077] The outer layer sheet of W5 was produced by the following procedure. First, a plain weave (Fabric B) tarpaulin base fabric (0.3 mm thick) was prepared by weaving polyester fiber yarn (750 denier polyester monofilament) at an arrangement density of 60 warp threads / 5 cm and 60 weft threads / 5 cm. This base fabric was impregnated with a polyvinyl chloride resin paste (product name: Paste PVC, manufactured by Kaneka Corporation) to produce an outer layer sheet (0.4 mm thick) made of tarpaulin.

[0078] [Table 2]

[0079] (Raw material for rubber composition) EPDM: "EPT K-9720" manufactured by Mitsui Chemicals, Inc. Zinc oxide: "Zinc oxide type 3" manufactured by Seido Chemical Industry Co., Ltd. Stearic acid: "Camellia Stearate" manufactured by NOF Corporation Calcium carbonate: Maruo Calcium Co., Ltd. "Super #1500" Carbon black: "Seast 3" manufactured by Tokai Carbon Co., Ltd. Process oil: Idemitsu Kosan Co., Ltd. "Diana Process Oil PW-90" Vulcanization accelerator TMTD: "Noccela TT" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Vulcanization accelerator MBT: "Noccela M" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0080] (Inner layer sheet) The inner layer sheets W4 to W5 listed in Table 1 were prepared as the inner layer sheets used as the waterproof sheets for each test specimen. The inner layer sheets W4 to W5 have the same structure and preparation method as the outer layer sheets W4 to W5 described above, except that the width direction dimensions of the inner layer sheets W4 to W5 are shorter than those of the outer layer sheets W4 to W5 due to their waterproof structure.

[0081] [Sealant] The sealants (adhesives) used to seal the internal space of each specimen were S1 to S5, as listed in Table 3. All of the sealants used were commercially available products (product names are listed in Table 3). The physical properties (hardness, tensile bond strength) of each sealant were measured in the physical property tests (hardness test, tensile bond strength test) described below, and the results are also shown in Table 3. In addition, the product names of the primers used to pre-prepare the upper surface (aluminum metal surface) of the wing roof to be coated with the sealant in order to improve adhesion between the sealant and the upper surface of the wing roof are also shown in Table 3 (all are commercially available products).

[0082] [Table 3]

[0083] (Sealant property testing) For each of the sealing materials S1 to S5, predetermined test pieces were prepared for each physical property test (hardness test and tensile bond strength test, which will be described later) at an ambient temperature of 23°C and a relative humidity of 65%. Then, after leaving them to stand (curing) for two days in the same environment (ambient temperature 23°C × humidity 65% ​​RH), each physical property test (hardness test and tensile bond strength test) was carried out.

[0084] (Hardness test) The hardness test of the sealant was conducted as a substitute test to understand the flexibility of the sealant after hardening, and was conducted in accordance with JISK6253 (2012), measuring the hardness of each sealant after hardening (after 2 days of curing). Specifically, a laminate consisting of three test pieces (100 mm x 100 mm x 2 mm thick sheets) prepared for hardness testing was used as a sample, and the hardness of the sealant after curing was measured at an ambient temperature of 23°C using a Type A durometer in accordance with the spring-type durometer hardness test specified in JIS K6253 (2012).

[0085] (Tensile adhesive strength test) The tensile bond strength test of sealants was conducted as a substitute test to understand the adhesion between the sealant (adhesive) and the upper surface (aluminum metal surface) of the wing roof, and was conducted in accordance with JIS K6849 (1994). A tensile force was applied perpendicular to the adhesive surface to measure the tensile bond strength (the stress at which the joint breaks) of each sealant. Specifically, a test piece prepared for the tensile bond strength test [square bar test piece: a test piece in which a joint (adhesive layer and primer layer) is formed between the opposing end faces (adhered surfaces) of a pair of adherends made of aluminum metal square bar (cross section: a square with one side of the adherend surface being 12.7 mm)] was used to measure the tensile bond strength (maximum tensile stress at which the joint breaks) in accordance with the tensile bond strength test specified in JIS K6849 (1994).

[0086] [Overview of each test specimen] The outline of each test specimen (waterproof structure) is shown below in the order of the test specimens listed in Tables 4 to 6 of the verification results described later. Each specimen was formed into a configuration (model) with the same thickness dimensions as the actual product, but with planar dimensions (width x length in the front-to-back direction) reduced for testing purposes compared to the actual product, so that it could be used for various tests (testing machines) to evaluate the waterproof structure, as described below. (The actual product is, for example, approximately 400 mm wide x 7 m long, whereas this was reduced to approximately 200 mm wide x 300 mm long.) Similarly, due to test constraints, the mounting structure below the specimen (the center frame, pair of hinge sections, and structure corresponding to the pair of wing roofs) was also formed into a flat plate overall, and the configuration and dimensions of each section were adjusted so that the planar dimensions were roughly the same as those of the specimen.

[0087] (Examples 1 to 4, Comparative Example 1) Using the outer layer sheet W1 (see Table 1) and sealants S1 to S5 (see Table 3) described above in the materials used section, a test specimen (waterproof structure) was produced in a manner similar to the installation procedure (center seat repair procedure) for a waterproof sheet for a wing vehicle in a waterproof structure without an inner layer sheet described in embodiment 1 above, in which the sealant sealed the internal space and adhered to at least the upper surface of the wing roof (aluminum metal plate) in the above-mentioned object to be attached. The waterproof structure of the outer layer sheet at both side edges and at the front and rear ends was the same as that described in the first embodiment. That is, the outer layer sheet was fixed to the upper surface of the wing roof via strip-shaped pressure plates and rivets, without being glued or caulked, and compressed in the thickness direction while being sandwiched (see Figure 2). The center sheet of each specimen was made of tarpaulin, the same as the outer layer sheet of W5, but was partially damaged in advance to form a damaged tarpaulin specimen W5' so that it could be applied to the deteriorated existing center sheet. The upper surface of the wing roof (aluminum metal plate) was pre-treated (primed) with a specified primer (listed in Table 3).

[0088] (Comparative Example 2) A waterproof structure having an outer layer sheet W1 was produced in the same manner as in Examples 1 to 4 and Comparative Example 1, except that the waterproof structure did not have a sealant to seal the internal space.

[0089] (Examples 5 to 8) Waterproof structures having a sealant S1 were fabricated in the same manner as in Example 1, except that outer layer sheets W2 to W5 (see FIG. 1) were used, respectively.

[0090] Examples 9 to 10 A waterproof structure with the same configuration as in Example 1 (outer layer sheet W1, sealant S1) was produced, except that each test specimen (each waterproof structure) was produced using the configuration described in the above-mentioned embodiment 2, which further included an inner layer sheet (W4 in Example 9, W5 in Example 10) and the installation procedure for the waterproof sheet for wing vehicles (center sheet repair procedure).

[0091] [Evaluation of waterproof structures: items, methods, and standards] For each test specimen shown in Tables 4 to 6, various performance characteristics (damage resistance, weather resistance, bending durability, waterproofness) were verified to determine whether a waterproof structure capable of solving the problem of the present application was obtained.

[0092] [Trauma resistance] (Test name) Drop impact test (Testing machine) not shown (Test Method) An 8.3 kg weight (weight) with a 35 cm extension length and a protrusion (blade) with an isosceles triangular cross section (vertex angle 35°, vertex radius of curvature 0.5 mm, height approximately 32 mm) integral with the rectangular main body was dropped from directly above toward the center of the specimen, with the top (tip) of the protrusion facing downward and the extension direction of the top aligned parallel to the longitudinal direction of the specimen (extension direction of the outer layer sheet), and the maximum height (separation distance between the outer layer sheet and the tip of the weight) at which the outer layer sheet was not damaged was determined.

[0093] (Judgment criteria) The damage resistance of each test piece was judged by the maximum height at which the outer layer sheet was not damaged (the higher the maximum height, the better the damage resistance). The maximum height at which the outer layer sheet will not be damaged is If it is over 8cm, it is classified as A. If it is between 6cm and 8cm, it is classified as B. Cases less than 6cm were rated C. From the viewpoint of suitability (resistance to external damage) for practical use in this application, a waterproof structure rated as either a or b was deemed to be acceptable.

[0094] [Weather resistance] (Test name) Sunshine weather resistance test (Testing equipment) A sunshine weather meter (Model S80 manufactured by Suga Testing Instruments Co., Ltd.) was used. (Test Method) Each test piece was newly prepared and subjected to a sunshine weathering test. Each test piece was set in the sunshine weather meter and subjected to a sunshine weathering test for 1,500 hours (equivalent to 10 years of outdoor exposure) according to the method specified in JIS B7951 (2007) (black panel temperature 63±3°C, spray cycle 18 minutes out of 120 minutes). After that, the appearance of the outer layer sheet was visually observed and the presence or absence of abnormalities (deterioration) in the appearance of the outer layer sheet was evaluated according to the following criteria.

[0095] (Judgment criteria) The weather resistance of each test piece (whether or not the outer layer sheet had deteriorated due to rainwater or ultraviolet rays) was judged by the presence or absence of abnormalities (deterioration) in the appearance of the outer layer sheet. After the test, the outer layer sheet was If no abnormalities (deterioration) were found in appearance, the product was rated as A. If minor appearance abnormalities (such as cracks that do not affect waterproofing) are found, the product will be rated B. If significant external abnormalities (cracks, tears, peeling, etc. that would impair waterproofing) were found, the product was rated C. From the viewpoint of suitability (weather resistance) for practical use in this application, a waterproof structure rated as either a or b was deemed to be acceptable.

[0096] [Bending durability] (Test name) Bench bending durability test (Testing machine) Bench-mounted bending durability testing machine (not shown) The bench-mounted bending durability tester is configured to be able to reproduce the opening and closing movements of a pair of wing roofs (made of aluminum metal) on the bench. Specifically, a drive unit [comprising a drive source (electric servo motor), reduction mechanism, opening / closing mechanism, and control unit (including an operation panel)] was attached to the underside of the test specimen (waterproof structure) and the body to be attached (both with planar dimensions of approximately 200 mm wide x 300 mm long in the front-to-back direction) on the table, for opening and closing a pair of wing roofs (aluminum metal plates) in any opening / closing cycle. In addition, the space on the table containing the test specimen (waterproof structure) and the body to be attached was used as a thermostatic chamber, and the ambient temperature was kept constant.

[0097] (Test Method) New test specimens were fabricated and subjected to bench bending durability tests. In light of actual environments, the ambient temperature on the bench (i.e., the surface temperature of the test specimen (waterproof structure) and the object to be mounted) was set to three different temperatures: approximately 50°C (high-temperature environment), approximately 23°C (normal temperature), and approximately -20°C (low-temperature environment). For each ambient temperature, the wing roof was opened and closed 10,000 times (opening angle 0° to 70°) according to the test pattern shown in Figure 10, with a 5-minute cycle time (time per opening and closing operation). This was an accelerated bench test simulating 10 years of repeated opening and closing operations (an average of about three times per day). After this, the condition of the sealant inside the interior space was visually inspected (after removing the outer layer sheet), and the presence or absence of sealant damage was evaluated according to the following criteria.

[0098] (Judgment criteria) The bending durability of each specimen (flexibility of the sealant) is judged mainly by the presence or absence of damage to the sealant. After the test, the sealant, etc. If no defects (cracks, etc.) were found under any ambient temperature, the test was rated as "A." If no significant defects (cracks, cracks, etc. that would impair waterproofing) were observed under any of the ambient temperatures, but minor defects (cracks, etc. that would not impair waterproofing) were observed under any of the ambient temperatures, the product was rated as B. If significant defects (cracks, breaks, etc. that would impair waterproofing) were observed under any of the ambient temperatures, the product was rated as C. From the viewpoint of suitability for practical use in this application (flexural durability), a waterproof structure rated as either a or b was deemed to be acceptable.

[0099] [Waterproof] (Test name) High-pressure water injection test (Testing equipment) High-pressure water jetting machine (not shown) (Test Method) Of the specimens that had undergone the previous bench bending durability test, those that had been tested at an ambient temperature of -20°C, which is considered to be the most severe condition for bending durability (flexibility of the sealant), were subjected to a high-pressure water jet test as is (after the removed outer layer sheet was reinstalled).At an ambient temperature of 23°C, a high-pressure water jet test was conducted using a high-pressure water jet machine (Kärcher Japan Co., Ltd.'s "High-Pressure Washer K-MINI") to spray high-pressure water evenly over the specimen (waterproof structure), including both side edges (water pressure: approximately 8 MPa, water discharge rate: approximately 5 L / min, water jet duration: 30 continuous minutes, distance between specimen and nozzle: 20 cm), verifying the waterproofing effect of the waterproof structure. To properly verify the waterproofing effect of the waterproof structure, each specimen was subjected to the high-pressure water spray test after the outer layer sheets, center sheet, and wing roofs were partially peeled off at both side edges. After the test, the interior space surrounded by the outer layer sheets, center sheet, and wing roofs (particularly the gaps between the center frame and the connecting parts of the left and right wing roofs) were visually inspected, and the presence or absence of water infiltration into the interior space was evaluated according to the following criteria.

[0100] (Judgment criteria) The waterproofing of each test piece (the waterproofing effect of the waterproof structure) was judged by whether or not water had penetrated into the interior space. After the test, the following was checked: If no water intrusion was observed, it was rated as A. If slight water infiltration (water seepage, etc., but not enough to impair waterproofing) is found, the product is rated B. If significant water infiltration (water infiltration to the extent that it impairs waterproofing, such as dripping water) was observed, the product was rated C. From the viewpoint of suitability (waterproofness) for practical use in this application, a waterproof structure rated as either a or b was deemed to be acceptable.

[0101] (Overall judgment) The criteria for the overall assessment (ranking) of a waterproof structure that can solve this problem were determined as follows, based on the results of the assessment of the four evaluation items mentioned above (damage resistance, weather resistance, bending durability, and waterproofness), and a rank of C or higher was considered to be a pass. Rank A: When all the above evaluation items were rated as "a," it was determined that there was no problem in practical use and was given the highest rank. Rank B: If there were no C ratings in the above evaluation items, but even one B rating, the product was ranked as slightly inferior, although there was no practical problem. Rank C: If there was no C rating in the waterproofing evaluation item, but even one C rating in the evaluation item other than waterproofing, the item was deemed to have no practical problems, but was ranked slightly lower than Rank B. Rank D: When the waterproofing evaluation item was rated as C, it was determined to be insufficient to solve the problem (failed).

[0102] [Verification results] The obtained test specimens (each waterproof structure) were evaluated by the above tests, and the results are shown in Tables 4 to 6.

[0103] (Change the type of sealant) [Table 4]

[0104] (Examples 1 to 4, Comparative Examples 1 and 2) In the waterproof structure (embodiment 1) without an inner layer sheet, the type of outer layer sheet was fixed at W1, and the type of sealant, including whether or not a sealant was used, was changed and compared. In both cases, the outer layer sheet (W1) was made of EPDM vulcanized rubber, which is said to have excellent weather resistance, and the base fabric (Fabric A) was embedded in a sufficiently thick waterproof layer, which was designed to provide both flexibility and reinforcement (resistance to external damage). This is probably because both the damage resistance and weather resistance were rated as A.

[0105] As in Examples 1 to 4, it can be seen that sealing the interior space surrounded by the outer layer sheet, center sheet, and wing roof with a sealant having a relatively low hardness (Type A) of 16 to 30 after hardening has an effect on bending durability (flexibility of the sealant) (rating a or b). Specifically, Examples 1 and 2, both of which used silicone-based sealants, and Example 4, which used a chloroprene rubber-based sealant, were rated as A for flexural durability, while Example 3, which used a polyurethane-based sealant, showed minor defects (minor cracks) in the sealant in a low-temperature environment of -20°C, resulting in a b for flexural durability.

[0106] Furthermore, as in Examples 1 to 4, it can be seen that the configuration in which the internal space is sealed with a sealant and the sealant is adhered to at least the upper surface (aluminum metal surface) of the wing roof has an effect on waterproofing (the waterproof effect is maintained even if both side edges of the outer layer sheet are partially peeled off from the wing roof) (rating a or b). Specifically, Examples 1 and 2, both of which used a silicone sealant, were given a rating of A for waterproofing (rank A in the overall evaluation), possibly because the adhesion (tensile bond strength) between the sealant and the aluminum metal surface was relatively good. Example 3, which used a polyurethane sealant, and Example 4, which used a chloroprene rubber sealant, were given a rating of B for waterproofing (rank B in the overall evaluation), possibly because the adhesion (tensile bond strength) between the sealant and the aluminum metal surface was not particularly sufficient.

[0107] On the other hand, the waterproof structure of Comparative Example 1 had a relatively high sealant hardness (Type A) level of 43, which may have made it difficult for the sealant to maintain flexibility after hardening, and in the above-mentioned bending durability test (opening and closing the wing roof 10,000 times), significant damage (cracks) was observed in the sealant at all ambient temperatures (rating C).As a result, in a subsequent high-pressure water spray test conducted using the same test specimen, no waterproofing effect was observed, and the waterproofing was also rated C, resulting in an overall rating of Rank D (failure).

[0108] Furthermore, in the waterproof structure of Comparative Example 2, in which the internal space was not sealed (airtight) with a sealant, in the high-pressure water spray test, water was allowed to penetrate into the internal space from the areas where both side edges of the outer layer sheet were partially peeled off from the wing roof, resulting in a waterproofing rating of C and an overall rating of Rank D (failure).

[0109] (Changed the type of outer layer sheet) [Table 5]

[0110] (Examples 1, 5 to 8) In the waterproof structure (Embodiment 1) not having an inner layer sheet, the type of outer layer sheet W1 was changed based on the waterproof structure of Example 1 in which the type of sealant was S1, and a comparison was made. In both cases, the internal space was sealed with a sealant (S1) that had a relatively low hardness (Type A) of 25 after hardening, and was adhered to at least the upper surface of the wing roof (aluminum metal surface), so both the bending durability and waterproofing were rated as A.

[0111] In the evaluation of external damage resistance, Example 1 (rated a), in which the thickness (total thickness) of the outer layer sheet containing the base fabric was 1.1 mm, received a rating of b (rank B in the overall evaluation). Examples 5 and 6, in which the same type of base fabric (Fabric A) was embedded in or laminated with a waterproof layer made of vulcanized rubber or synthetic resin but a thinner outer layer sheet of 0.7 mm was used, received a rating of b (rank B in the overall evaluation). Furthermore, compared to Example 1 (rated a), Example 7, in which an outer layer sheet without a base fabric as a reinforcing material was used, had the same thickness (total thickness) of 1.1 mm, and Example 8, in which an outer layer sheet with a base fabric (Fabric B) but a structure in which the base fabric was simply impregnated with synthetic resin (tarpaulin) and therefore had a thickness (total thickness) of only 0.4 mm, received a rating of c (rank C in the overall evaluation).

[0112] In the weather resistance evaluation, Examples 1, 5, and 7, in which the waterproof layer was an outer layer sheet formed from EPDM-based vulcanized rubber, were all rated as A, but Example 6, in which the waterproof layer was an outer layer sheet formed from a general-purpose synthetic resin (polyvinyl chloride resin), suffered from minor appearance abnormalities (minor cracks) and was rated as B, and Example 8, in which the resin material impregnated into the base fabric was an outer layer sheet formed from a general-purpose synthetic resin (polyvinyl chloride resin), suffered from significant appearance abnormalities (significant cracks) and was rated as C.

[0113] (Add inner layer sheet) [Table 6]

[0114] (Examples 9 and 10) In a waterproof structure (embodiment 2) further including an inner layer sheet, the type of outer layer sheet was W1 and the type of sealing material was S1, and as the inner layer sheet, Example 9 used a W4 waterproof sheet (consisting of only a waterproof layer), and Example 10 used a W5 waterproof sheet (tarpaulin), and the two were compared. In all cases, even though the waterproof structure further included an inner layer sheet within the internal space, the bending durability was rated as A (rank A in the overall evaluation).

[0115] From all of the above verification results, it was confirmed that at least the internal space surrounded by the outer layer sheet, center seat, and wing roof is sealed with a sealant that remains flexible even after hardening, and that the sealant is adhered to at least the upper surface of the wing roof, resulting in a waterproof structure for the center seat of a wing vehicle that has a longer lifespan (highly durable and can maintain its waterproof effect for a long period of time). [Explanation of symbols]

[0116] 1 Waterproof structure 2 Wing vehicle waterproof sheet 21 Outer layer sheet 241 242 waterproof layer 243 Base fabric 3. Sealant 4 Retaining plate 5 Rivets 6. Interior space 100 Wing Vehicles 101 Center Frame 102 Wing Roof 103 Wing Roof 105 center seat

Claims

1. A waterproof structure for a center seat for a wing vehicle, comprising a center sheet stretched to cover a boundary portion between a center frame extending in the front-rear direction at the center of the width direction of the top of a cargo bed and a wing roof rotatably connected to both sides of the center frame, and a waterproof sheet for a wing vehicle stretched to cover the center sheet, The waterproof sheet for a wing vehicle is formed to be wider than the center sheet, and includes at least a belt-shaped outer layer sheet disposed across the center sheet, with both side edges of the waterproof sheet for a wing vehicle being fixed to the upper surface of the wing roof, an internal space surrounded by the outer layer sheet, the center sheet, and the wing roof is sealed with a sealing material that remains flexible even after hardening; The waterproof structure for a center seat for a wing vehicle, wherein the sealant is adhered to at least the upper surface of the wing roof.

2. 2. The waterproof structure for a center seat for a wing-type vehicle according to claim 1, wherein the sealant is a one-component silicone-based sealant that cures at room temperature.

3. The waterproof structure of a center seat for a wing vehicle as described in claim 1, wherein both side edges of the outer layer sheet are fixed to the upper surface of the wing roof via a strip-shaped pressure plate and rivets, without being glued or caulked.

4. 2. The waterproof structure for a center seat for a wing vehicle according to claim 1, wherein the waterproof sheet for a wing vehicle further includes a strip-shaped inner layer sheet that covers the center seat within the internal space.

5. A waterproof sheet for a wing vehicle used in the waterproof structure of the center seat for a wing vehicle according to any one of claims 1 to 4, The outer layer sheet is a waterproof sheet for a wing vehicle, in which a base fabric serving as a reinforcing material is embedded or laminated in a waterproof layer made of vulcanized rubber or synthetic resin.

6. 6. The waterproof sheet for a wing vehicle according to claim 5, wherein the waterproof layer of the outer layer sheet is formed of vulcanized rubber, and the rubber component contains ethylene-propylene-diene terpolymer (EPDM).

7. A method for repairing a center seat for a wing vehicle, the method comprising: using a waterproof sheet for a wing vehicle stretched over the center sheet stretched over a boundary portion between a center frame extending in the front-rear direction at the center of the width direction of the top of the cargo bed and a wing roof rotatably connected to both sides of the center frame; a step of disposing, as the waterproof sheet for the wing vehicle, at least a strip-shaped outer layer sheet formed wider than the center sheet so as to straddle the center sheet, and fixing both side edge portions of the outer layer sheet to the upper surface of the wing roof; A method for repairing a center seat for a wing vehicle, comprising the steps of sealing the interior space surrounded by the outer layer sheet, the center seat, and the wing roof with a sealant that remains flexible even after hardening, and adhering the sealant to at least the upper surface of the wing roof.

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