JP2012171533A - Panel structure for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body frame that provides sufficiently high torsion rigidity and forms a flexible structure desirable against a shock load in a collision or the like as a panel structure of fiber-reinforced resin capable of also achieving reduction in weight.SOLUTION: This panel structure for an automobile can support the load from the front and back axles of the automobile and is formed of a fiber-reinforced resin extending in the longitudinal direction of the automobile. The panel structure has a stiffener extending in an 8-shaped closed loop shape over the longitudinal part of the structure in a plane view.

Description

  The present invention relates to an automotive panel structure, and more particularly to an automotive panel structure made of a fiber reinforced resin capable of realizing an excellent flexible structure against a high torsional rigidity and a collision load as a body frame.

  In the current automobile structure, the frame and the panel are basically assembled in a cross-girder structure. In general, a body frame of an automobile usually requires high torsional rigidity around a central axis extending in the vehicle longitudinal direction, that is, around an axis along the center of the vehicle body. In particular, a rigidity that can sufficiently withstand the torsion caused by the load received from the front and rear axles is required. In order to ensure such a torsional rigidity, a normal vehicle type such as a sedan uses a pillar and a roof to ensure the torsional rigidity at the center of the vehicle body. However, since this method cannot be used particularly in an open car (roadster), a torsional rigidity is conventionally increased by adding a frame to the vehicle body. However, it is usually difficult to increase the rigidity sufficiently.

  On the other hand, automobiles are required to have a basic configuration that ensures the safety of passengers in the event of a collision, etc. Performance and manufacturing cost reduction are required. The structure for improving the safety of the occupant includes not only the high torsional rigidity of the vehicle body frame as described above, but also, for example, in order to properly protect the occupant in the passenger compartment from the impact load at the time of a collision, especially from the front and rear. On the other hand, it is also desirable that the body frame has a flexible structure.

  As a structure that satisfies the demand for reducing the weight of the vehicle body in order to improve fuel efficiency, studies are underway to use at least a part of the constituent material as a fiber reinforced resin. For example, Patent Document 1 proposes a structure in which a part of a vehicle body skeleton is made of a fiber reinforced resin as a configuration for reducing the weight of the vehicle body and ensuring the safety of an occupant during a collision. In the structure disclosed in Patent Document 1, a vehicle body skeleton part and a vehicle compartment part constituting the lower part of the vehicle body are formed independently, and the vehicle body skeleton part is formed of a fiber reinforced resin so that impact energy absorption performance is provided in that part. It is intended to have it.

JP 2010-23706 A

  When considering constructing at least a part of the body frame with fiber reinforced resin, as described above, the current automobile structure is basically a structure in which the frame and the panel are assembled in a grid pattern. If followed as it is, it is difficult to make a fiber reinforced resin because there are a lot of branch-shaped portions, there are many stress concentration portions, and there are many places where the load transmission path is inappropriate for the fiber reinforced resin material. On the other hand, since the fiber reinforced resin is basically an anisotropic material, it is possible to relatively easily provide high characteristics in a specific direction by performing an appropriate structural design. Accordingly, it is possible to provide a high torsional rigidity as described above, a configuration with a preferable flexible structure against an impact load at the time of a collision, and the like. However, in order to achieve such a desirable form, a special technical concept and design concept that are not confined by the structure of a conventional normal vehicle body frame are required. In the above-mentioned Patent Document 1, there is no technical idea regarding improvement of torsional rigidity.

  In view of the above circumstances, the object of the present invention is to provide sufficiently high torsional rigidity to an open car (roadster) as well as a normal car model such as a sedan, and at the time of a collision. An object of the present invention is to realize a vehicle body frame that can constitute a flexible structure with respect to an impact load as a panel structure of a fiber reinforced resin that can be achieved while reducing the weight.

  In order to solve the above problems, an automotive panel structure according to the present invention is a panel structure made of a fiber reinforced resin that can support a load from the front and rear axles of a vehicle and that extends in the vehicle front-rear direction. In particular, the structure has a stiffener extending in a closed loop shape in the shape of a letter 8 over the front and rear portions of the structure.

  In the automotive panel structure according to the present invention, it is preferable that at least the inner structure portion of the 8-shaped closed loop formed by the stiffener has a surface structure. Of course, the surface structure portion can also be provided on the outer structure portion of the 8-shaped closed loop shape by the stiffener. Further, the 8-shaped central portion of the 8-shaped closed loop shape formed by the stiffener can be formed in an intersecting shape portion or an approach / separation shape portion.

  In such an automotive panel structure according to the present invention, a panel structure is formed by a stiffener portion and a surface structure portion. However, since the stiffener portion is configured in an 8-shaped closed loop shape, The stiffener cross-shaped part (the part extending so as to cross) or the approaching / separating shape part (the part extending so as to cross but extend so as to approach and separate without actually crossing) A high torsional rigidity is imparted by being able to develop a high tensile or compressive resistance against the torsional force applied to the entire panel structure. At the same time, the ring-shaped portion of the figure 8 has a structure that is easy to deform while maintaining the ring shape, and this portion becomes a structure portion that can easily realize a flexible structure. The flexible structure will be realized. And since a panel structure consists of fiber reinforced resin, the lightness which is an original characteristic can also be expressed. As a result, a vehicle panel structure that can exhibit sufficiently high torsional rigidity, can form a preferable flexible structure with respect to an impact load at the time of a collision, and can achieve weight reduction can be realized.

  In the automotive panel structure according to the present invention, at least a part of the reinforcing fibers of the fiber reinforced resin constituting the stiffener is at least the cross shape portion or the approaching / separating shape portion of the stiffener at the center of the figure 8. Preferably extends along the stiffener extension direction. In particular, it is preferable that at least a part of the reinforcing fibers of the fiber reinforced resin constituting the stiffener extend continuously along the stiffener extending direction. If comprised in this way, in the said 8 character center part, a stiffener will be able to express higher tensile or compression resistance with respect to the torsional force added to the whole panel structure body, and higher torsional rigidity as the whole panel structure body is attained. Achieved.

  Further, the 8-shaped central portion of the 8-shaped closed loop shape by the stiffener is located substantially at the central portion in the vehicle front-rear direction, but the closed-loop shaped 8-shaped central portion is arranged in the vehicle width direction. It is preferable that it is located in the substantially central part. If comprised in this way, the torsional rigidity balanced as the whole panel structure body can be expressed now. Further, the flexible structure with the ring-shaped portion of the figure 8 is also balanced with respect to the entire panel structure.

  Moreover, in the automotive panel structure according to the present invention, it is preferable that the entire structure portion having the stiffener extending in the above-mentioned 8-shaped closed loop shape is integrally formed. By the integral molding, the target rigidity can be expressed more easily, and the productivity can be greatly improved.

  The following advantages can be obtained by the integral molding. First, as structural advantages, (1) continuity of the reinforcing fiber itself and (2) continuity of strain between the reinforcing fibers with respect to external force can be obtained, so that high structural characteristics are expressed and the characteristics are stable. And the like. In addition, as an advantage for formability (easiness to make), (1) cost can be reduced because there is no need for molds and processes for assembling individual parts and processes for assembling them. (2) Regarding accuracy, The dimensional accuracy of the structure does not accumulate errors when assembling other parts, so it can be molded with high accuracy. (3) Regarding the RTM moldability, the reinforcing fiber is filled in the mold before resin impregnation, so the shape (particularly curved surface) ) It is easy to arrange the reinforcing fibers in the direction along the direction, and the finished molded product is compatible with the shape and direction of the reinforcing fibers, so that it can stably exhibit high characteristics against external force, etc. Benefits are gained.

  The basic structure portion of the automobile panel structure according to the present invention is a structure portion having a stiffener extending in the shape of an 8-shaped closed loop as described above. It is also possible to employ a structure in which another structure made of fiber reinforced resin, which extends in the vertical direction, is joined to the side surface in the vehicle width direction of the structure portion having the extending stiffener. For example, as shown in an embodiment described later, a floor side portion of a vehicle body frame is configured by the basic structure portion of the above-described automotive panel structure according to the present invention, and the side wall panel equivalent portion of the vehicle body frame is formed with respect to the structure portion. Further, it is possible to configure a structure in which another structure made of fiber reinforced resin that extends in the vertical direction is joined. With this configuration, most of the necessary basic components of the body frame can be configured, and the weight reduction and torsional rigidity of the body frame can be effectively realized.

  It is preferable that the another structure is joined to a stiffener of a structure portion having a stiffener extending in the shape of a closed loop of the figure 8. If it does in this way, the joint strength of both structure parts can be maintained high. Moreover, it is preferable that said another structure is also a structure which has the stiffener extended in a closed loop shape. Thereby, another structure part also has high torsional rigidity, and high torsional rigidity can be expressed also as the whole panel structure for vehicles by which both structures were joined.

  In the present invention, the reinforcing fiber of the fiber reinforced resin used is not particularly limited, and carbon fiber, glass fiber, aramid fiber, and the like can be used, and a hybrid configuration in which these reinforcing fibers are combined can also be adopted. From the viewpoint of realizing high torsional rigidity, a form including carbon fiber having high rigidity and strength, easy molding, and easy structural design is preferable. In particular, it is preferable that the fiber reinforced resin constituting the structural body portion having the stiffener extending in at least the above-mentioned 8-shaped closed loop shape contains carbon fiber. Further, the matrix resin of the fiber reinforced resin is not particularly limited, and either a thermosetting resin or a thermoplastic resin 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.

  As described above, according to the automotive panel structure of the present invention, the structure including the stiffener made of fiber reinforced resin and extending in the shape of a closed loop of an 8-shape can reduce the weight of the vehicle body frame and open car. A sufficiently flexible structure for a torsional rigidity and a favorable flexible structure against an impact load such as a collision can be realized even for (roadster), and a desirable structure as an automotive panel structure can be provided.

It is a perspective view of the panel structure for vehicles concerning one embodiment of the present invention. FIG. 2 is a perspective view of an 8-shaped closed loop portion of the automobile panel structure of FIG. 1. FIG. 3 is a perspective view of an eight-shaped closed loop shape portion different from FIG. 2. It is a perspective view of another structure part joined to the 8-shaped closed loop shape part of the panel structure for motor vehicles of FIG. It is sectional drawing which follows the AA line of FIG. 2, Comprising: It is sectional drawing which shows the various cross-sectional shape examples of a stiffener.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an automotive panel structure according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an automobile panel structure. The panel structure 1 extends in the vehicle front-rear direction XX, and is from axles 2, 3 that are rotational axes of wheels 4 before and after the automobile. It is configured to be able to support the load of. The panel structure 1 includes a panel structure made of fiber reinforced resin extending in the vehicle front-rear direction XX. In this embodiment, the panel structure 1 mainly constitutes a floor side portion of the body frame, and is joined to the horizontal panel portion 5 extending mainly in the horizontal direction and both sides of the horizontal panel portion 5 in the vehicle width direction YY. Further, it is configured in an integrated structure with the upper and lower panel portions 6 as another structure extending in the vertical direction. The horizontal panel portion 5 is configured as a portion having a stiffener 7 extending in a closed loop shape of an eight shape over the front and rear portions of the panel structure 1 in plan view in the present invention, and the upper and lower panel portions 6 on both sides. Are joined to the stiffener 7 of the horizontal panel portion 5. In the horizontal panel portion 5, at least an inner structure portion of an 8-shaped closed loop shape by the stiffener 7 is configured as a surface structure portion 8 having a surface structure.

  The horizontal panel portion 5 is configured as shown in FIG. The 8-shaped central portion 10 of the 8-shaped closed loop shape portion 9 formed by the stiffener 7 is configured as an intersecting shape portion that the stiffener 7 extends. The central portion of the figure 8 is positioned at the central portion of the panel structure 1 in the vehicle longitudinal direction XX, and is also positioned at the central portion in the vehicle width direction YY.

  Regarding the structure of the center of the figure 8 in the figure 8 closed loop shape part, in addition to the structure shown in FIG. 2, for example, a structure as shown in FIG. In the horizontal panel portion 11 shown in FIG. 3, the 8-shaped central portion 14 of the 8-shaped closed loop shape portion 13 by the stiffener 12 approaches and separates the stiffeners 12 extending on both sides without crossing each other. It is formed in the approaching / separating shape part.

  The upper and lower panel part 6 as another structure extended in the up-down direction is configured, for example, as shown in FIG. The upper and lower panel portions 6 also have a stiffener 21 formed as a closed-loop shape portion 22 extending in an 8-shape, and an 8-shaped central portion 23 of the 8-shaped closed-loop shape portion 22 is formed on both sides thereof. The extending stiffeners 21 are formed in an approaching / separating shape portion that approaches and separates from each other without intersecting. At least the inner structure portion of the 8-shaped closed loop shape by the stiffener 21 is configured as a surface structure portion 24 having a surface structure.

  Various forms can be adopted as the cross-sectional structure of the stiffener in the horizontal panel portion 5 and the upper and lower panel portions 6. For example, various forms as illustrated in FIG. 5 can be adopted in a cross-sectional form taken along 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 the automotive panel structure 1 according to the present embodiment configured as described above, since the panel structure 1 having an integrated structure is made of a fiber reinforced resin, first, the body frame can be reduced in weight. And this panel structure 1, especially the horizontal panel part 5, since the stiffener 7 is comprised in the closed loop shape part 9 of the figure 8 shape, In the cross-shaped part of the stiffener 7 of the figure 8 center part 10 mainly. (In the structure shown in FIG. 3, the stiffeners 12 approaching and moving away from each other) have a high tensile or compression resistance against the twisting force (bidirectional twisting force) applied to the entire panel structure by the stiffener 7 extending diagonally. It can be expressed. Therefore, high torsional rigidity is given to the entire panel structure 1. Along with the provision of this high torsional rigidity, the ring-shaped portion of the figure 8 has a structure that is easily deformed as an overall shape while maintaining the shape of the ring-shaped portion of the figure 8 on the front side and the ring-shaped portion of the figure 8 on the rear side. It becomes. That is, these parts are configured as a flexible structure that is easily deformed by a load from the surroundings. Therefore, a desirable flexible structure of an automotive panel structure capable of absorbing impact energy by appropriate deformation with respect to an impact load at the time of a collision or the like is realized.

  By joining the upper and lower panel parts 6 formed as the closed loop shape part 22 in which the stiffener 21 extends in the shape of the figure 8 to the horizontal panel part 5, the above flexible structure by the horizontal panel part 5 is not substantially impaired. The flexible structure in the vertical direction is mainly formed by the ring-shaped portion of the figure 8 of the closed loop shape portion 22, and a desirable flexible structure of the automotive panel structure is realized also in this direction. Furthermore, the addition of the upper and lower panel portions 6 further improves the torsional rigidity of the panel structure 1 as a whole, and realizes a higher torsional rigidity.

  The automotive panel structure according to the present invention can be applied to automobiles of all types of vehicles, but can also be applied to open cars (roadsters) that have been difficult to apply in the past.

DESCRIPTION OF SYMBOLS 1 Automotive panel structure 2, 3 Axle 4 Wheel 5 Horizontal panel part 6 Upper and lower panel part 7 Stiffener 8 Surface structure part 9 8-shaped closed loop shape part 10 8 character center part 11 Horizontal panel part 12 Stiffener 13 8 Character-shaped closed loop shape portion 148 character central portion 21 stiffener 22 8 closed-loop shape portion 23 extending in the shape of 8 character shape central portion 24 surface structure portion 31, 33, 35, 37, 39, 42, 44 stiffener portion 32 , 34, 36, 38, 41, 43, 45 Planar structure 40 Core material

Claims (11)

  A panel structure made of fiber-reinforced resin that can support a load from the front and rear axles of an automobile and that extends in the vehicle front-rear direction. An automotive panel structure comprising a stiffener extending.   The automotive panel structure according to claim 1, wherein at least an inner structure portion of the 8-shaped closed loop shape by the stiffener has a surface structure.   The automotive panel structure according to claim 1 or 2, wherein an 8-shaped central portion of the 8-shaped closed loop shape formed by the stiffener is formed in an intersecting shape portion or an approach / separation shape portion.   At least a part of the reinforcing fiber of the fiber reinforced resin constituting the stiffener extends along the stiffener extending direction in at least the cross-shaped portion or the approaching / separating shape portion of the 8-shaped central portion of the stiffener. Item 4. The automobile panel structure according to Item 3.   The automotive panel structure according to claim 4, wherein at least a part of the reinforcing fibers of the fiber reinforced resin constituting the stiffener extends continuously along the stiffener extending direction.   The automotive panel structure according to any one of claims 1 to 5, wherein an 8-shaped central portion of the 8-shaped closed loop shape by the stiffener is located at a central portion in the vehicle width direction.   The automotive panel structure according to any one of claims 1 to 6, wherein the entire structure portion having a stiffener extending in the shape of a closed loop of the figure 8 is integrally formed.   8. Another structure made of fiber reinforced resin, which extends in the vertical direction, is joined to the side surface in the vehicle width direction of the structure portion having the stiffener extending in the shape of a closed loop of the figure 8 shape. The automotive panel structure according to any one of the above.   The automobile panel structure according to claim 8, wherein the another structure is joined to a stiffener of a structure portion having a stiffener extending in the shape of a closed loop of the figure 8 shape.   The automobile panel structure according to claim 8 or 9, wherein the another structure has a stiffener extending in a closed loop shape.   The automotive panel structure according to any one of claims 1 to 10, wherein a fiber reinforced resin constituting a structural body portion having a stiffener extending in at least the 8-shaped closed loop shape includes carbon fibers.

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