JP5700276B2 - Panel structure - Google Patents

Description

The present invention relates to a panel structure using FRP structural elements (FRP: Fiber Reinforced Plastic) that can be suitably applied to automobile panels and the like.

  FRP, especially CFRP (Carbon Fiber Reinforced Plastic), is widely deployed in various industrial fields because it is lightweight and can exhibit high strength and high rigidity. For example, in the field of automobiles, FRPs are being studied for various parts in order to improve fuel efficiency by reducing weight, facilitating manufacturing by integrally forming a vehicle body structure, increasing strength and rigidity, and the like. However, since current metal automobile structures are basically assembled in a frame-like structure with a frame and a panel, it is often difficult to follow the shape to make an FRP. In other words, following the conventional shape as it is and making it into FRP, there are many branch shape parts, and there are places where FRP molding is difficult, places where stress concentration is likely to occur, making it difficult to make use of the characteristics of FRP, In some cases, the characteristics of the FRP that can exhibit particularly high strength and rigidity in the orientation direction of the reinforcing fibers cannot be successfully used in the load transmission path.

  On the other hand, when considering the use of FRP in automobile structures, it is necessary to design the shape of the structure so that it can be molded by FRP. For that purpose, the structure of the existing metal structure is constrained. It is desirable that the degree of freedom of design is high. In this regard, in particular, in electric vehicles, fuel cell vehicles, hybrid cars, etc., an electric motor can be used as a power source for vehicle travel, and the electric motor has a high degree of freedom in the vehicle mounting position. The degree of freedom is greatly improved. Therefore, for example, the shape and the degree of freedom of the structure of the passenger compartment structure for constituting the passenger compartment are greatly increased. Therefore, it is relatively easy to adopt the FRP structure in such an electric vehicle. Further, an automobile that can use an electric motor as a power source for running the vehicle has been attracting attention as a vehicle adapted to the global environment because it emits less carbon dioxide in total. In particular, the concept of LCA (Life Cycle Assessment) has been adopted in recent years, and the reduction of carbon dioxide emissions throughout the life from the vehicle manufacturing stage including materials to the use of the vehicle to the scrapped vehicle is being evaluated.

  On the other hand, automobiles are required to have a configuration for ensuring the safety of passengers at the time of a collision, etc. as a basic requirement specification. Excellent mass productivity and manufacturing cost reduction are required. As a structure for improving the safety of passengers, for example, a rigid structure that can suppress deformation as much as possible for the passenger compartment, which is the passenger's living space, and the vehicle front part and rear part connected to the passenger compartment structure part On the other hand, a flexible structure (also called a crushable structure) is used to effectively absorb impacts from the outside during collisions (such as front and rear collisions) and minimize the impact on the passenger compartment. A design philosophy that makes it preferable is also attracting attention.

  As a configuration for ensuring the safety of passengers in the event of a collision including the weight reduction of the vehicle body, for example, a structure in which the vehicle body skeleton portion is made of fiber reinforced resin has been proposed (for example, Patent Document 1). The structure disclosed in Patent Document 1 is formed by independently forming a vehicle body skeleton portion and a vehicle compartment portion constituting the lower portion of the vehicle body, and forming the vehicle body skeleton portion from a fiber reinforced composite material, and impact energy absorption performance in that portion. It is made to have.

  In the structure disclosed in this Patent Document 1, the FRP structure is adopted for the vehicle body skeleton part which has few problems in terms of FRP molding in shape, and there are many curved parts and the like, and it is considered that FRP molding is usually difficult to perform. The vehicle compartment component employs a configuration that is formed independently of the vehicle body skeleton. Since the vehicle body skeleton part and the vehicle compartment component part are formed independently, there is a limit to improvement of productivity, particularly mass productivity, and it is not a particularly advantageous structure in terms of reducing manufacturing costs. In addition, structural improvements for impact energy absorption and the like have been added to the vehicle body skeleton located in the lower part of the passenger compartment, but for the passenger compartment, the safety of passengers has been improved. Therefore, the device such as a rigid structure that can suppress deformation as much as possible is not particularly considered. In other words, for passengers in the passenger compartment, although consideration has been given to ensuring safety by absorbing impact energy by the vehicle body skeleton, from the aspect of ensuring passenger safety by suppressing deformation of the passenger compartment, It cannot be said that the structure is fully considered.

JP 2010-23706 A

  As described above, when considering the FRP of an automobile structure as described above, for example, a part or member that has been configured with a metal or the like, a shape having a curved portion or the like while having a high degree of freedom in design. However, it is desirable that the FRP can be easily formed, and that the FRP has properties such as strength and rigidity that can be utilized to the maximum.

Therefore, the object of the present invention is to design and manufacture the FRP structure by paying attention to the concept of a structural element forming each part of the structural body, and by adding a special device to the structural element, and it can be molded easily a desired shape with a degree of freedom of high design, and capable of easily exhibit excellent characteristics FRP also has a collection of structural elements, moreover, automobile as described above An object of the present invention is to provide a panel structure using FRP structural elements that can be easily expanded to a general structure as well as a structural structure.

In order to solve the above-mentioned problems, a panel structure according to the present invention comprises a fiber-reinforced resin molded body whose planar shape is a pentagonal or hexagonal polygon, and stiffeners are formed on all sides of the polygon. It is formed in a closed loop shape to form a closed loop ridge structure, the inside of the closed loop shape is formed into a plane structure , and is bent along at least one of the diagonal lines of the polygon, or configured to be foldable. The FRP structural element is composed of a plurality of concatenated aggregates .

  Here, the cross-sectional shape of the stiffener, that is, the cross-sectional shape of the ridge may take various shapes, for example, a polygon such as a hat shape, a triangle, a rectangle, a trapezoid, and a hexagon, a C shape, and an I shape. Various cross-sectional shapes such as, T-shaped, Z-shaped, H-shaped, inverted L-shaped, inverted U-shaped and the like, and a standing wall-shaped rib shape can be exemplified. Further, as a cross-sectional form of the stiffener, a sandwich structure in which a core material made of solid, hollow, foamed material or the like is interposed can be adopted. Furthermore, as the inner surface structure of the closed loop shape, a fiber reinforced resin plate (skin plate) structure having a relatively small thickness is typically adopted, but a core material made of foam material or the like is interposed between the skin plates. It is also possible to adopt a sandwich structure, a structure in which a space is formed between the skin plates, and the like.

In such a panel structure according to the present invention, as the FRP structure element, stiffeners are formed in a closed loop shape on all sides of the polygon that forms the outline of the FRP structure element. The stiffener having the closed loop ridge structure realizes sufficiently high strength and rigidity as the entire structural element. In addition, since the inside of the closed loop shape is configured as a plane structure, the function of transmitting an in-plane load to the plane structure part, which is lower in strength and rigidity than the stiffener part, while ensuring the form of the panel element as a whole FRP structure element It is possible to provide a function of absorbing the transmission load from the stiffener portion. For example, the stiffener part is mainly restrained against bending load, both the stiffener part and the surface structure part against tensile load, and the stiffener part or buckling against compressive load. A structure supported by the surface structure portion can be formed. Therefore, it is possible to give one FRP structural element the necessary form and function as a panel element while giving the FRP unique high strength and high rigidity characteristics due to the fact that the material is FRP. The overall lightweight can be secured. Since the planar shape of the FRP structural element is formed as a pentagon or hexagon, it is possible to easily connect the same kind of polygons or a combination of pentagons or hexagons. Thus, a panel structure having a required area and shape can be manufactured by the connection. Furthermore, if the buckling behavior of the surface structure is used, it is possible to realize a structure in which the entire FRP structural element does not break at once when a large impact load or the like is applied, but the breakage partially proceeds sequentially. It becomes possible. Therefore, in the panel structure according to the present invention in which such FRP structural elements are composed of a plurality of connected assemblies, as described above, the FRP structural elements have a pentagonal or hexagonal planar shape. Since it is formed in a square shape, desired connection can be easily performed by joining the same kind of polygonal FRP structural elements or by joining in a state where pentagonal or hexagonal polygonal FRP structural elements are combined. It is possible to manufacture a panel structure having a required area and shape by the connection. When connecting, adjacent FRP structural element shapes and sizes can be changed as appropriate, and the connecting pitch of the FRP structural elements can be changed or changed as appropriate. By appropriately changing the shape, size, and connecting pitch in this way, it becomes possible to partially change the characteristics of the panel structure, for example, mechanical properties such as strength and rigidity, which are optimal for each part of the panel structure. It becomes possible to give a special characteristic. It is also possible to give a part of the panel structure having a certain area a partly isotropic characteristic. Of course, it is possible to have substantially uniform characteristics throughout the panel structure. Further, the panel structure can be easily bent or bent partially, and the entire panel structure can be easily formed into a desired form.

The FRP structural element of the panel structure according to the present invention has a structure that is bent along at least one of the diagonal lines of the polygon or is configured to be foldable . That is, if the planar shape is a pentagonal FRP structural element, there are five diagonal lines, and if the planar shape is a hexagonal FRP structural element, there are nine diagonal lines, but along at least one of these diagonal lines Bending allows the FRP structural element to bend or curve across both sides of its diagonal. If a plurality of FRP structural elements are connected using such an FRP structural element, it becomes possible to form a bent shape or a bent shape as a connected structure, and the FRP structural element according to the present invention has a larger size. It can be used as a structural element of a structure having a more complicated shape.

  When a larger structure is formed by connecting FRP structural elements, the stiffener constituting the closed loop ridge structure is formed integrally with the stiffener constituting the closed loop ridge structure of another adjacent FRP structural element. Alternatively, a structure that can be integrally joined is also possible. In such a structure, the strength and rigidity of the entire structure configured as an FRP structural element can be further increased, and the volume of the stiffener portion in the structure can be minimized, so that the entire structure can be reduced. It is possible to contribute to reduction of the amount of material used and weight reduction.

In the FRP structural element of the panel structure according to the present invention, the reinforcing fiber of the fiber-reinforced resin molded body is not particularly limited, and various reinforcing fibers such as carbon fiber, glass fiber, and aramid fiber can be used. Yes, and a hybrid configuration combining these reinforcing fibers is also possible, but in order to achieve good formability and productivity while realizing high strength and rigidity, it must contain carbon fibers. Is preferred.

  The matrix resin of the fiber reinforced resin molded product is not particularly limited, and any of thermosetting resins and thermoplastic resins can be used. A typical example of the thermosetting resin that can be used is an epoxy resin. For molding in the case of using a thermosetting resin, it is possible to apply a molding method such as RTM (Resin Transfer Molding) or press molding using a prepreg. In the case of a thermoplastic resin, injection molding can be applied in addition to the above molding method. Usable thermoplastic resins include, for example, polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamideimide, polyphenylene sulfide, polyphenylene oxide. Polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polystyrene, ABS, liquid crystal polyester, a copolymer of acrylonitrile and styrene, and the like can be used. A mixture of these may also be used. Moreover, what was copolymerized like the copolymer nylon of nylon 6 and nylon 66 may be used. Furthermore, depending on the required properties of the molded product to be obtained, flame retardants, weather resistance improvers, other antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, conductive fillers, etc. It can be added.

  In particular, when an FRP structural element that is bent along at least one of the diagonal lines of the polygon is used, the curved portion of the panel structure can be configured more easily. Further, the stiffeners constituting the closed-loop ridge structure of the adjacent FRP structural elements are integrally formed or integrally joined, so that the panel structure as a whole is more desirable. It becomes possible to have strength and high rigidity characteristics.

  In the panel structure, a relative height may be given to the arrangement density of the stiffeners constituting the closed loop ridge structure of the FRP structural element. In order to give a relative height to the arrangement density of the stiffener, FRP structural elements of different sizes and shapes are combined, the arrangement pitch of the FRP structural elements is changed, and the size and shape of the stiffener itself are changed. It can be achieved by doing. By partially increasing the stiffener arrangement density as necessary, it becomes possible to appropriately increase the strength and rigidity of the part, and by reducing the stiffener arrangement density partially and relatively It is possible to minimize the amount of material used for the panel structure as a whole, and to contribute to weight reduction and cost reduction of the entire panel structure.

  Such a panel structure according to the present invention can be applied to various fields, but is particularly suitable as a panel structure for automobiles. Among them, as described above, as a panel structure for an automobile that uses an electric motor as a power source for driving a vehicle such as an electric vehicle, a fuel cell vehicle, and a hybrid car, which has a relatively high degree of freedom in designing the structure. Is preferred.

  For example, as the panel structure according to the present invention, the above-described automobile panel structure is configured as a structure for constituting a passenger compartment, and the entire structure from the front side to the rear side of the passenger compartment. The monocoque structure is integrally formed of fiber reinforced resin, and has a hook-like structure portion that opens toward the rear side and / or the front side on the front side and / or rear side of the structure. In addition, the curved portion of the bowl-shaped structure portion can be configured as a panel structure formed using an FRP structural element that is bent along at least one of the polygonal diagonal lines. In addition, the said bowl-shaped structure part is a concept including the bowl-shaped structure part of all shapes opened toward the front-back direction of a structure (front-back direction of a motor vehicle), such as a half-open dome shape and a square bowl-shaped shape. .

Thus, the monocoque in which the entire structure from the front side to the rear side of the passenger compartment is integrally formed of fiber reinforced resin by connecting and appropriately combining the FRP structural elements of the panel structure according to the present invention It becomes possible to produce a casing structure having a structure. That is, by providing the casing structure in the casing structure, it is possible to integrally configure the main structure part for configuring the casing as a monocoque structure integrally with fiber reinforced resin. Therefore, compared with the conventional structure as described in Patent Document 1 described above, the vehicle interior structure for the automobile in which the vehicle interior component and the portion including the vehicle base portion located below the vehicle interior are integrally formed. It is a structure of a new concept that is fundamentally different from the prior art in that it is in the form of a body and all these parts are integrally formed. For ordinary sedan-type automobiles, the saddle-like structure part includes both a front saddle-like structure part that opens toward the rear side and a rear saddle-like structure part that opens toward the front side. However, for some vehicle types such as a hatchback type, a structure having only a front saddle-like structure is possible. Such a saddle-like structure portion can be molded integrally with the entire vehicle compartment structure as long as the die-cutting structure at the time of molding is secured. Since the entire vehicle compartment structure formed of fiber reinforced resin has a monocoque structure, it is possible to easily secure the rigidity required throughout the vehicle compartment components while achieving weight reduction. The required rigid structure of the room is achieved and the safety for the passenger is improved. Further, when at least a part of the monocoque structure is a sandwich structure using a fiber reinforced resin as a skin, a lighter weight and a rigid structure can be obtained. And since such a vehicle compartment structure can be constructed in a monocoque structure including the vehicle base portion located at the lower part of the vehicle compartment, it becomes possible to integrally form the whole, and the number of parts is extremely reduced, Manufacture is facilitated, and excellent productivity, particularly excellent mass productivity can be obtained, and the manufacturing cost can be reduced. Further, as described above, the degree of freedom of vehicle body design is greatly increased in an automobile that enables the use of an electric motor as a power source, and this advantage can be reflected in the degree of freedom of the monocoque structure. Simplification, simplification of shape, easy demolding at the time of molding, and the like, and further improvement in productivity and the like can be achieved.

  Moreover, in the above vehicle interior structure, the hook-like structure portion is a support portion for a load transmitted from a vehicle structure portion arranged adjacent to the outside of the hook-like structure portion in the front-rear direction of the structure body. It is possible to have a structured structure. Since the passenger compartment structure as described above constitutes the main structural part of the passenger compartment, the front side of the automobile compartment, that is, the front part of the vehicle, is arranged on the rear side. Can arrange a rear portion of the vehicle compartment, that is, a rear portion of the vehicle. There is a possibility that a load such as an impact may be applied to the bowl-shaped structure portion of the structure due to the front and rear bumps on the front and rear portions, and the load at that time is applied to the casing structure having a rigid structure. It is to be received. As a result, the safety of passengers in the passenger compartment is more reliably ensured. At this time, if the front part and rear part of the vehicle are configured in a crushable structure, the load that is to be transmitted to the vehicle interior while appropriately absorbing the impact due to the collision by the crushable structure is applied to the vehicle. It is possible to realize an overall configuration ideal for ensuring the safety of passengers, which is to stop by the rigid structure of the room structure. Further, the front part and the rear part may have a structure for attaching drive system parts such as wheels, axles, and suspensions. In that case, the load related to driving from these drive system components may be transmitted from the front part or the rear part to the bowl-like structure part of the passenger compartment structure. It is to be received by the structure. As a result, it is possible for the vehicle compartment structure to incorporate a function as a support structure for the drive system components, and to realize a vehicle compartment structure for an automobile that can further reduce manufacturing costs. In particular, in the present invention, such a desirable vehicle compartment structure is realized as a panel structure composed of an assembly of FRP structural elements according to the present invention.

Thus, Oite the FRP structural elements of the panel structure according to the present invention, a structural element made of a fiber-reinforced resin, by configuring the superior strength, particular forms capable articulating comprises a rigid, high design It is possible to provide a structure having a desired overall shape with a certain degree of freedom. The panel structure according to the present invention can be easily manufactured at low cost by connecting such FRP structural elements, and the panel structure can exhibit the excellent lightness and mechanical properties of FRP. As a whole, it is possible to provide the desired load transmission characteristics, strength, and rigidity. Especially, as a panel structure for automobiles, especially as a cabin structure, a structure with the desired form and characteristics can be manufactured with excellent mass productivity and low cost. It becomes possible to obtain.

It is a perspective view of the FRP structure element of the panel structure which concerns on one embodiment of this invention. It is a perspective view of the FRP structure element of the panel structure which concerns on another embodiment of this invention. It is a perspective view of the panel structure concerning one embodiment of the present invention. It is a top view of the panel structure equivalent to FIG. It is a fragmentary sectional view which follows the AA line of FIG. 3, Comprising: It is a fragmentary sectional view which shows the various cross-sectional shape examples of a stiffener. It is a top view of the panel structure which concerns on another embodiment of this invention, Comprising: It is a top view which shows the example which provided high and low to the arrangement | positioning density of stiffeners. It is a fragmentary top view of the panel structure concerning another embodiment of the present invention. It is a schematic perspective view which shows the various examples of the bending form of the FRP structural element which concerns on another embodiment of this invention. It is a perspective view of the compartment structure as a panel structure concerning another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an FRP structural element of a panel structure according to an embodiment of the present invention. In this embodiment, the FRP structural element 1 is formed into a hexagonal polygonal planar shape, and the entire structural element is formed as a fiber reinforced resin molded body, particularly as a carbon fiber reinforced resin molded body. A stiffener 2 is formed in a closed loop shape (in a closed loop shape extending in a polygonal line) on all sides of the hexagonal shape to form a closed loop ridge structure portion 3, and an inner side of the closed loop shape (closed loop ridge structure portion 3 The inner surface portion of the surface structure portion 4 extends in a planar shape. The stiffener 2 constituting the closed-loop ridge structure portion 3 can be molded integrally with the stiffener constituting the closed-loop ridge structure portion of another adjacent FRP structure element (hexagonal or pentagonal FRP structure element), or integrally It is possible to construct so that it can be joined.

  Further, the FRP structural element 1 is configured to be foldable along at least one of the diagonal lines of the polygon, that is, in the case of a hexagon, a total of nine diagonal lines exist. ing. An example of the bending form will be described later.

FIG. 2 shows an FRP structural element of a panel structure according to another embodiment of the present invention. In this embodiment, the FRP structural element 6 is formed in a polygon having a pentagonal planar shape. The whole is formed as a molded body of fiber reinforced resin, particularly as a molded body of carbon fiber reinforced resin. Stiffeners 7 are formed in a closed loop shape (closed loop shape extending in a polygonal line) on all sides of the pentagonal shape to form a closed loop ridge structure portion 8, and the inner side of the closed loop shape (closed loop ridge structure portion 8 The inner portion of the surface structure 9 is configured to spread in a planar shape. The stiffener 7 constituting the closed-loop ridge structure 8 can also be molded integrally with the stiffener constituting the closed-loop ridge structure of another adjacent FRP structural element (pentagonal or hexagonal FRP structural element), or integrally. It is possible to construct so that it can be joined. In the case of this pentagonal FRP structural element 6, there are a total of five diagonal lines, but they are configured to be foldable along at least one of them.

  The FRP structural elements 1 and 6 as described above are formed as a plurality of concatenated aggregates, so that, for example, flat panel structures 11 and 21 as shown in FIGS. 3 and 4 and FIG. A panel structure can be formed as a passenger compartment structure for constituting a passenger compartment of an automobile as shown. The FRP structural elements 1 and 6 are connected by integrally forming the stiffeners constituting the closed-loop ridge structure portion of the adjacent FRP structural elements, or by integrally bonding (adhering or fusing) the stiffeners. Can be done.

  Specifically, for example, as shown in FIGS. 3 and 4, flat panel structures 11 and 21 are formed by appropriately combining hexagonal FRP structural elements 12 and pentagonal FRP structural elements 13, as necessary. A square FRP structural element 14 is also combined. Such flat panel structures 11 and 21 are applicable to all fields. Each FRP structural element has a stiffener closed-loop ridge structure and is connected by the stiffener portion, so that the panel structure as a whole can exhibit high strength and rigidity as well as the FRP structural element single portion. In addition, the inside of the stiffener closed loop ridge structure portion is configured as a lightweight surface structure portion, and these surface structure portions spread in the surface direction of the panel structure body via each stiffener portion, so that the entire panel structure body While achieving weight reduction, the desired form of the entire panel structure is ensured.

  The cross-sectional shape of the stiffener in the FRP structural element and the panel structure is not particularly limited, and various shapes as described above can be adopted. For example, various forms as illustrated in FIG. 5 can be taken in the cross-sectional form seen along the line AA in FIG. In the form shown in FIG. 5A, a hollow stiffener portion 31 having a hexagonal cross-sectional shape is formed, and a surface structure portion 32 is formed between the stiffener portions 31. In the form shown in FIG. 5B, the cross-sectional shape is formed in a stiffener portion 33 having a quadrangular shape, and the surface structure portion 34 is formed between the stiffener portions 33. In the form shown in FIG. 5C, the cross-sectional shape is formed in a circular stiffener portion 35, and the surface structure portion 36 is formed between the stiffener portions 35. In the form shown in FIG. 5D, the cross-sectional shape is formed in an I-shaped stiffener portion 37, and a surface structure portion 38 is formed between the stiffener portions 37. In the form shown in FIG. 5 (E), the cross-sectional shape is formed in a hexagonal stiffener portion 39, but in the hexagonal stiffener portion 39 made of fiber reinforced resin, the core material 40 (for example, foamed resin or the like) is formed. The core material) is filled to form a stiffener portion, and a surface structure portion 41 is formed between the stiffener portions. In the form shown in FIG. 5 (F), the cross-sectional shape is formed in a hollow stiffener part 42 having a hexagonal shape, and the planar structure part 43 extends through the hollow part of the stiffener part 42. In the form shown in FIG. 5 (G), the cross-sectional shape is formed into a trapezoidal rectangular hollow stiffener portion 44 (half the shape of the hexagonal hollow stiffener portion), and the stiffener portion 44 is a surface structure portion. 45 is arranged only on one side. Various forms other than the illustrated example can be adopted. What kind of stiffener cross-sectional shape is selected may be appropriately determined according to the function, mechanical characteristics, surface form, and the like required for the panel structure.

  In a conventional panel structure composed of a stiffener having a cross-beam structure, vertical and horizontal stiffeners intersect at a right angle. On the other hand, in the panel structure formed by connecting the FRP structural elements according to the present invention, the crossing angle of the stiffener portions can be made larger than a right angle. As a result, the stress concentration at the intersection of the stiffeners when transmitting a load can be reduced, so that the panel structure made of the FRP structural element according to the present invention can increase its structural strength. .

  In addition, in the conventional panel structure made of a stiffener having a cross-beam structure, a stiffener extending in one direction transmits a load in that direction, whereas in the panel structure made of an FRP structural element according to the present invention, the stiffener portion has a stiffener portion. Since the load is transmitted while being branched in a plurality of directions, the load can be efficiently supported as the entire panel structure.

  For example, when this structure is applied to an automobile floor panel, the load at the time of a frontal collision or a side collision can be efficiently supported by the entire floor panel. Even when a local impact is applied to a part of the floor panel, as described above, the FRP structural element according to the present invention transmits a load while distributing a load while avoiding a critical stress concentration. Therefore, a floor panel having a high structural strength can be obtained.

  Further, as described above, in the panel structure of the present invention, it is also possible to give a relative height to the arrangement density of the stiffeners constituting the closed loop ridge structure of the FRP structure element in the panel structure. It is. For example, as shown in FIGS. 6A and 6B, in the panel structures 51 and 52, portions 53 and 54 having a high stiffener arrangement density can be provided as appropriate. How to provide high stiffener placement density should be determined appropriately according to the functions and mechanical characteristics partially required for the panel structure, while considering the weight reduction of the entire panel structure. Good.

  For example, when this structure is applied to a floor panel of an automobile, the mounting parts of the engine and suspension arranged on the front side of the vehicle can be firmly attached to the floor by increasing the stiffener arrangement density of the portion corresponding to the front side of the vehicle. Is possible. Also, by increasing the stiffener density at the center of the floor panel, it is possible to provide a structure that efficiently supports the load during a side collision.

  Further, when the panel structure is formed by connecting the hexagonal FRP structural elements as described above, for example, by connecting different (different forms) FRP structural elements in the middle of the connection, for example, the connected hexagonal It is also possible to change the axial direction of the FRP structural element midway. For example, as shown in FIG. 7, when the hexagonal FRP structural element 61 in the axial direction X is connected and the hexagonal FRP structural element 62 in the axial direction Y is connected, a hexagonal FRP structure having a concave shape is formed between the two connected regions. By interposing the element 63 and the pentagonal FRP structure element 64, it is possible to change the axial direction of the hexagonal FRP structure element between the X direction and the Y direction. This structure is effective when anisotropy is given to the strength and rigidity and the direction is desired to be changed in the middle, and may be adopted as necessary.

Further, the FRP structural element of the panel structure according to the present invention can be configured to be bent along at least one of polygonal diagonal lines. For example, as shown in FIGS. 8A to 8D, stiffeners 71 a, 71 b, 71 c, 71 d and surface structures 72 a, 72 b, 72 c are formed into polygons that form ridge lines (hexagons in the illustrated example). In the FRP structural element composed of 72d, 72d, one of the diagonal lines in the polygon is folded into the folding shafts 73a, 73b, 73c, 73d, 73e (in the form shown in FIG. 8D, two folding shafts (folding shaft (1) 73d , And can be bent along the folding axis (2) 73e)). By using such a folded FRP structural element, it is possible to form a relatively complicated panel-shaped portion such as a curved portion.

  By combining various forms of FRP structural elements, for example, it is possible to integrally form a panel structure 81 as a cabin structure having a shape as shown in FIG. In order to obtain an integrated structure, a plurality of these FRP structural elements can be integrally joined, and depending on the overall shape, the panel structure 81 can be formed by integral molding. The panel structure 81 as a vehicle interior structure is configured as a monocoque structure in which the entire structure is integrally formed of fiber reinforced resin. A front saddle-like structure part 82 that opens toward the rear side and a rear saddle-like structure part 83 that opens toward the front side are formed on the front and rear sides of the panel structure 81 in the vehicle longitudinal direction. Yes. The curved portions of the bowl-shaped structures 82 and 83 are formed by using FRP structural elements that are bent along at least one of the polygonal diagonal lines as described above.

  In the panel structure 81 as such a vehicle interior structure, for example, an FRP structure including the stiffeners 2 and 7 formed in the closed loop ridge structure portions 3 and 8 and the surface structure portions 4 and 9 as described above. By adopting a structure in which a plurality of elements 1 and 6 are connected, high rigidity and strength (particularly bending rigidity and strength) of the panel structure 81 as a whole are ensured mainly by the connection structure of the stiffeners 2 and 7. The desired shape and surface form of the panel structure 81 as a whole are secured via the parts 4 and 9. In particular, since the front and rear saddle-shaped structures 82 and 83 can be configured with high strength and high rigidity, it is possible to greatly improve the safety of passengers against large impact loads applied during front and rear collisions. Become. In addition, for example, it can be supported by the entire width of the floor portion for vertical bending, and high rigidity is ensured by a stiffener portion extending in an oblique direction (direction oblique to the vehicle longitudinal direction) against twisting. The In addition, it can be supported with full floor width for longitudinal compression load, and it is supported by distributing the load over the floor width for load from the side of the vehicle (for example, impact load due to side collision). It becomes possible. Furthermore, it is also possible to give isotropic mechanical characteristics over the entire floor portion of the panel structure 81. For example, by connecting the entire floor portion to the hexagonal FRP structural element 1 as described above. It is possible to realize isotropic mechanical characteristics. When it is desired to have a partial rigidity distribution, for example, by appropriately combining the pentagonal FRP structure element 6 and the hexagonal FRP structure element 1, the FRP structure in a folded form This can be achieved by appropriately combining the elements.

  Further, by partially changing the connecting pitch of the hexagonal FRP structural element 1 and the pentagonal FRP structural element 6 (specifically, by appropriately incorporating FRP structural elements 1 and 6 having different sizes) It is also possible to partially change the characteristics of a specific part of the panel structure 81. Furthermore, by making good use of the buckling behavior of the surface structures 4 and 9, the panel structure 81 is not destroyed at a stretch over a wide range when a large impact load is applied. Thus, it is possible to design a structure in which partial destruction proceeds sequentially through the buckling behavior of 9, and it is possible to design the panel structure 11 as a vehicle compartment structure considering even the destruction to more desirable specifications.

  A rigid structure of the passenger compartment is effectively achieved by the integrated passenger compartment structure 81 having such bowl-like structures 82 and 83, and at the same time, lightweight is ensured by being made of fiber reinforced resin. Furthermore, if the whole is integrally formed, good productivity, particularly mass productivity, and cost reduction can be achieved.

The panel structure using the FRP structural element according to the present invention can be developed in various fields, and in particular, there is a degree of freedom in the mounting position of a panel structure such as a passenger compartment structure for an automobile, particularly a vehicle driving power source. It is particularly suitable for high electric vehicles, fuel cell vehicles, hybrid cars and the like.

DESCRIPTION OF SYMBOLS 1, 6 FRP structural element 2, 7 Stiffener 3, 8 Closed-loop ridge structure part 4, 9 Plane structure part 11, 21 Panel structure 12 Hexagonal FRP structural element 13 Pentagonal FRP structural element 14 Tetragonal FRP structural element 31, 33 , 35, 37, 39, 42, 44 Stiffener portion 32, 34, 36, 38, 41, 43, 45 Planar structure portion 40 Core material 51, 52 Panel structure 53, 54 Location with high stiffener arrangement density 61, 62 Hexagonal FRP structural element 63 Recessed hexagonal FRP structural element 64 Pentagonal FRP structural element 71a, 71b, 71c, 71d Stiffeners 72a, 72b, 72c, 72d Surface structure portions 73a, 73b, 73c, 73d, 73e Bending shaft 81 Panel structure 82, 83 as a passenger compartment structure

Claims (8)

The planar shape consists of a fiber reinforced resin molded body formed into a pentagonal or hexagonal polygon, and stiffeners are formed in a closed loop shape on all sides of the polygon to form a closed loop ridge structure. An FRP structural element that is configured to have a planar structure on the inside and that is bent or configured to be foldable along at least one of the diagonal lines of the polygon includes a plurality of connected assemblies. A panel structure characterized by comprising: Said stiffener to form a closed loop ridge structure, a stiffener which constitutes a closed loop ridge structure of another FRP structural element adjacent or are integrally molded, and is bondable constructed integrally with claim 1 The panel structure described in 1 . The panel structure according to claim 1 or 2, wherein the reinforcing fibers of the fiber-reinforced resin molded body include carbon fibers . The panel structure according to any one of claims 1 to 3 , wherein a curved portion of the panel structure is configured by using an FRP structure element that is bent along at least one of the diagonal lines of the polygon. The panel structure according to any one of claims 1 to 4, wherein stiffeners constituting a closed loop ridge structure of adjacent FRP structural elements are integrally formed or integrally joined. The panel structure according to any one of claims 1 to 5 , wherein in the panel structure, a relative height is given to the arrangement density of the stiffeners constituting the closed loop ridge structure of the FRP structure element. The panel structure in any one of Claims 1-6 comprised by the panel structure for motor vehicles. The automobile panel structure is configured as a structure for constituting a passenger compartment, and a monocoque structure in which the entire structure from the front side to the rear side of the passenger compartment is integrally formed of fiber reinforced resin. And having a hook-like structure portion that opens toward the rear side and / or the front side on the front side and / or the rear side of the structure, and the curved portion of the hook-like structure portion is 8. A panel structure according to claim 7 , wherein the panel structure is formed using FRP structural elements folded along at least one of the polygonal diagonals.

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