JP6372141B2 - Shock absorbing structure and vehicle outer plate member having the same - Google Patents

Description

  The present invention relates to an impact absorbing structure and a vehicle outer plate member including the same.

  Conventionally, a so-called sandwich structure is known as a member constituting an automobile body or the like (for example, Patent Document 1). The sandwich structure described in Patent Document 1 is disposed between an outer panel and an inner panel made of carbon fiber reinforced resin and spaced from each other in the thickness direction, and between the outer panel and the inner panel. A plurality of ribs. The rib is formed in a cylindrical shape, and when the energy due to the impact is applied to the outer panel, the rib is deformed and broken to absorb the energy due to the impact.

JP 2012-131335 A

  However, in the sandwich structure described in Patent Document 1, the longitudinal end of the rib has a small contact area with the outer panel and the inner panel, so that the bonding area between the outer panel and the inner panel and the rib is increased. I can't take it. For this reason, there exists a problem that the rigidity of the whole sandwich structure is comparatively low, and energy absorption amount falls.

  Accordingly, an object of the present invention is to provide an impact absorbing structure capable of increasing the amount of energy absorption when energy due to impact is applied, and a vehicle outer plate member including the same.

  A first aspect of the present invention is an impact absorbing structure including a plate-like intermediate member disposed between a pair of fiber reinforced resin plates. The intermediate member is formed in a corrugated cross section, and the wave-shaped top of the intermediate member is joined to the inner surface of the fiber reinforced resin plate.

  A second aspect of the present invention is a vehicle outer plate member having the shock absorbing structure.

  ADVANTAGE OF THE INVENTION According to this invention, the energy absorption amount when the energy by an impact is added can be increased, and the outer-plate member for vehicles provided with this can be provided.

It is a disassembled perspective view of the hood provided with the impact-absorbing structure which concerns on embodiment of this invention. It is explanatory drawing which shows the state which loaded the load into the hood provided with the impact-absorbing structure which concerns on embodiment of this invention. It is a FS diagram of a hood provided with an impact absorption structure concerning an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  An automobile hood (bonnet) 10 having an impact absorbing structure according to an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the hood 10 is disposed between a pair of fiber reinforced resin plates 11 and 12 that are disposed at intervals in the plate thickness direction, and the pair of fiber reinforced resin plates 11 and 12. A plate-like intermediate member 13. The fiber reinforced composite material constituting the hood 10 is also referred to as a sandwich panel.

  The shock absorbing structure according to the present embodiment is not limited to an automobile hood, and can be applied to a vehicle outer plate member such as a door panel, a bumper, a trunk lid, a rear gate, a fender panel, a side body panel, and a roof panel. Note that this shock absorbing structure is not limited to the vehicle outer plate member, and can be applied to various components.

  The fiber reinforced resin plates 11 and 12 constitute the surface layers (front surface and back surface) of the shock absorbing structure. In the present embodiment, the fiber reinforced resin plate (front side member) 11 constitutes the outer layer of the shock absorbing structure, and the fiber reinforced resin plate (back side member) 12 constitutes the outer layer of the shock absorbing structure. The fiber reinforced resin plates 11 and 12 are formed in a plate shape from a fiber reinforced resin (fiber reinforced plastic). As the fiber reinforced resin, various fiber reinforced resins such as carbon fiber reinforced resin (CFRP), glass fiber reinforced resin (GFRP), and aramid fiber reinforced resin (AFRP) can be used. The plate thickness of the fiber reinforced resin plates 11 and 12 is, for example, about 0.8 to 1 mm, and the plate thickness of the entire hood 10 is, for example, about 10 mm.

  The intermediate member 13 constitutes a core layer having a shock absorbing structure. The intermediate member 13 is formed in a cross-sectional corrugated shape (corrugated shape), and the corrugated top portion 14 of the intermediate member 13 is joined (adhered) to the inner surfaces 15 and 16 of the fiber reinforced resin plates 11 and 12 by an adhesive. Yes. As the intermediate member 13, a leaf spring made of fiber reinforced resin, metal, or synthetic resin can be used. In the present embodiment, the cross section of the intermediate member 13 is formed in a sine wave shape, but is not limited thereto, and the cross section of the intermediate member 13 may be formed in a triangular wave shape, a trapezoidal wave shape, or the like.

  In the present embodiment, a plurality of intermediate members 13 are arranged at intervals in a direction intersecting with the stacking direction of the shock absorbing structure constituting the hood 10, and the wave-shaped top portions 14 of each intermediate member 13 are made of fibers by an adhesive. The reinforcing resin plates 11 and 12 are joined (adhered) to the inner surfaces 15 and 16, respectively. A plurality of intermediate members 13 having a certain area are arranged in the shock absorbing structure, and the intermediate member 13 is locally disposed in the stacking direction of the shock absorbing structure while ensuring a certain degree of initial rigidity of energy input by the shock. This is for easy crushing. For example, the area (size) per sheet of the intermediate member 13 is set to be smaller as the adhesive force (or adhesion area) between the fiber reinforced resin plates 11 and 12 and the intermediate member 13 is increased. Further, the area (size) per sheet of the intermediate member 13 is set to be smaller as the spring constant of the leaf spring constituting the intermediate member 13 is increased.

  When molding the hood 10, first, an adhesive is applied to the wave-shaped top portions 14 on both surfaces of the intermediate member 13. Next, the fiber reinforced resin plates 11 and 12 are superposed on both surfaces of the intermediate member 13, and these laminates (the pair of fiber reinforced resin plates 11 and 12 and the intermediate member 13) are sandwiched from above and below and pressed and heated. By doing so, the adhesive applied to the wave-shaped top portions 14 on both surfaces of the intermediate member 13 is melted and cured, and the fiber-reinforced resin plates 11 and 12 and the intermediate member 13 are bonded by this adhesive. . In addition, this shaping | molding method is an example and it is possible to employ | adopt various methods.

  As an adhesive that bonds the fiber reinforced resin plates 11 and 12 and the intermediate member 13, an epoxy resin adhesive, a urethane resin adhesive, or the like can be used. The adhesive that bonds the fiber reinforced resin plates 11 and 12 and the intermediate member 13 may be a thermosetting adhesive or a thermoplastic adhesive.

  Energy absorption by the shock absorbing structure according to the present embodiment will be described with reference to FIGS.

  The impactor (head impactor) P used in the pedestrian protection test is collided with the hood 10 configured as described above, and the input load (reaction force) F to the hood 10 and the stroke of the hood 10 ( Displacement) S was measured. FIG. 3 shows an FS diagram of the hood 10, that is, a graph showing the relationship between the input load to the hood 10 and the stroke S of the hood 10.

[Phase 1]
As shown in FIG. 2 (a), when energy by impact is input to the surface of the hood 10 (fiber reinforced resin plate 11), the fiber reinforced resin plate 11 on the front side becomes the fiber reinforced resin plate 12 side on the back side. It is displaced to. Then, as shown in FIG. 2 (b), a force in a direction substantially orthogonal to the displacement direction of the fiber reinforced resin plate 11 acts on the joint portion of the intermediate member 13, and the fiber reinforced resin plates 11, 12 and the intermediate member 13 are intermediate. Peeling occurs at the joint 17 with the member 13. At this time, the energy of the impact is input to the fiber reinforced resin plate 11, and until the separation occurs at the joint 17 between the fiber reinforced resin plates 11 and 12 and the intermediate member 13, the reaction force of the hood 10 is as shown in FIG. The peak reaction force increases to F1.

[Phase 2]
After that, as shown in FIG. 2C, the intermediate member 13 released from the bonding with the fiber reinforced resin plates 11 and 12 is crushed and deformed in the stacking direction of the shock absorbing structure, and FIG. ), The intermediate member 13 is in a substantially flat state. That is, the intermediate member 13 composed of a leaf spring is fully extended and becomes a plate shape parallel to the fiber reinforced resin plates 11 and 12. At this time, the reaction force of the hood 10 is changed from the peak reaction force F1 to the reaction force until the intermediate member 13 is crushed and deformed in the stacking direction of the shock absorbing structure and the intermediate member 13 becomes substantially flat as shown in FIG. It becomes small to F2.

[Phase 3]
Further, thereafter, as shown in FIG. 2 (e), the intermediate member 13 becomes substantially flat, and the entire hood 10 (fiber reinforced resin plates 11, 12, intermediate member 13) is bent and deformed. At this time, as shown in FIG. 3, the reaction force of the hood 10 increases again from the reaction force F2 to the second peak reaction force F3 (F1>F3> F2).

  Below, the effect by this embodiment is demonstrated.

  (1) The shock absorbing structure according to the present embodiment includes a fiber reinforced resin plate (front side member) 11 and a fiber reinforced resin plate (back side member) 12 that are disposed in pairs in the thickness direction, and a pair of these. A plate-like intermediate member 13 disposed between the fiber reinforced resin plates 11 and 12. The intermediate member 13 is formed in a corrugated cross section, and the wave-shaped top portions 14 of the intermediate member 13 are joined to the inner surfaces 15 and 16 of the fiber reinforced resin plates 11 and 12, respectively.

  When energy by impact is input to the surface of the hood 10 (fiber reinforced resin plate 11), first, the joint portion 17 (see FIG. 2B) between the fiber reinforced resin plates 11 and 12 and the intermediate member 13 is peeled off. Meanwhile, the intermediate member 13 is crushed in the stacking direction of the shock absorbing structure. Until the joint 17 between the fiber reinforced resin plates 11 and 12 and the intermediate member 13 is peeled off, the bending rigidity is ensured, the reaction force of the hood 10 is increased, and the energy due to the impact is absorbed. After that, the reaction force of the hood 10 is once reduced until the intermediate member 13 is crushed and deformed in the stacking direction of the shock absorbing structure and the intermediate member 13 becomes substantially flat. Further, after that, the intermediate member 13 is in a substantially flat state, and the entire hood 10 is bent and deformed, whereby the reaction force of the hood 10 is increased again, and energy due to impact is further absorbed. That is, in the initial input of energy due to impact (phase 1 and phase 2), the joint 17 between the fiber reinforced resin plates 11 and 12 and the intermediate member 13 is peeled off, and the intermediate member 13 is crushed in the stacking direction of the shock absorbing structure. In the late input stage (phase 3) in which the energy is absorbed and the stroke becomes large, the hood 10 as a whole is bent and deformed to absorb the energy. For this reason, according to the shock absorbing structure according to the present embodiment, it is possible to effectively absorb energy due to the shock.

  (2) A plurality of intermediate members 13 are arranged at intervals in a direction intersecting the plate thickness direction of the fiber reinforced resin plates 11 and 12 (lamination direction of the shock absorbing structure), and the wave-shaped top portions of the intermediate members 13 14 are respectively joined to the inner surfaces of the fiber reinforced resin plates 11 and 12.

  By doing in this way, it can suppress that an excessive reaction force generate | occur | produces with respect to the input of the energy by an impact. For this reason, the hood 10 can have a structure in which the hood 10 (intermediate member 13) is easily crushed locally in the stacking direction while ensuring a certain degree of initial rigidity of energy input due to impact. Therefore, the hood 10 can effectively absorb energy due to impact.

  By the way, the shock absorbing structure of the present invention and the vehicle outer plate member provided with the shock absorbing structure have been described by taking the above-described embodiment as an example. However, the present invention is not limited to this embodiment, and other modifications are possible within the scope of the present invention. Various embodiments can be adopted.

10 Hood (Vehicle outer plate member)
DESCRIPTION OF SYMBOLS 11 Fiber reinforced resin board 12 Fiber reinforced resin board 13 Intermediate member 14 Wave-shaped top part 15 of intermediate member Inner surface 16 of fiber reinforced resin board Inner surface of fiber reinforced resin board

Claims (3)

A fiber reinforced resin plate disposed in a pair at intervals in the plate thickness direction;
A plate-shaped intermediate member disposed between the pair of fiber-reinforced resin plates,
The intermediate member is formed in a cross-sectional corrugated shape, the wave-shaped top of the intermediate member is joined to the inner surface of the fiber reinforced resin plate,
As for the joining force of the intermediate member to the fiber reinforced resin plate, energy by impact is input to the fiber reinforced resin plate, one of the fiber reinforced resin plates is displaced toward the other fiber reinforced resin plate, When a force in a direction perpendicular to the displacement direction of the fiber reinforced resin plate acts on the joint, the joint is set so that separation occurs at the joint between the fiber reinforced resin plate and the intermediate member. Shock absorbing structure.   A plurality of the intermediate members are arranged at intervals in a direction crossing the plate thickness direction of the fiber reinforced resin plate, and the wave-shaped top portions of the intermediate members are respectively joined to the inner surface of the fiber reinforced resin plate. The shock absorbing structure according to claim 1, wherein: Vehicle outer plate member provided with a shock absorbing structure according to claim 1 or 2.

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