JP2007237944A - Composite structural material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite structural material capable of constituting a vehicle body frame making absorbing characteristics of impact energy and lightening compatible with each other. <P>SOLUTION: Sudden lowering of bending stress of a beam member is restrained by compression stress of a cylindrical body by providing the cylindrical body 12 for reinforcement an axis of which is extended in a direction where a bending load is applied between opposed inner surfaces of side walls 13, 14 of the beam member (side sill 6) making a hollow closed cross-section made of a light metal material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite structure material, and more particularly to a composite structure material suitable for a vehicle body frame.

For automobile bodies, further reduction in weight is desired from the viewpoint of reducing fuel consumption and improving steering response, and it is already practical to construct a frame with a drawn (extruded) material such as an aluminum alloy. It is provided. However, aluminum alloy has lower rigidity than steel, and if it is attempted to obtain rigidity equivalent to that of a steel frame, the cross-sectional area has to be increased. Therefore, weight reduction cannot be promoted so much. Therefore, as a structural material that can cope with such inconvenience, a composite material in which a plate of a carbon fiber reinforced resin material is bonded to a structural material having a hollow closed cross section formed of a light alloy material has been proposed (see Patent Document 1). I want to be)
Table 99/010168

  However, the requirements for the structural material for automobile frames include not only high rigidity but also ability to absorb the impact at the time of collision with high efficiency. However, it was not possible to suppress a rapid stress drop after plastic deformation, and it was impossible to obtain satisfactory characteristics in terms of absorbability of impact energy at the time of collision.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to construct a vehicle body frame capable of achieving both high impact energy absorption characteristics and light weight. An object of the present invention is to provide a composite structure that can be used.

  In order to achieve such an object, claim 1 of the present invention is directed to a direction in which a bending load is applied between the opposing inner surfaces of the side walls 13 and 14 of the beam member (side sill 6) having a hollow closed section made of a light metal material. The reinforcing cylindrical body 12 having its axis extended is provided. In particular, the reinforcing cylindrical body is formed of a fiber reinforced resin material (Claim 2), or a plurality of the reinforcing cylindrical bodies are juxtaposed, and a part of the adjacent ones is elongated. It is preferable to overlap the direction and the direction perpendicular to the direction in which the bending load is applied (Claim 3).

  Further, in claim 4, the composite structural material according to any one of claims 1 to 3 is characterized in that a reinforcing flat plate 15 is bonded to a surface opposite to a surface to which a bending load is applied. It was supposed to be.

  According to the configuration of the first aspect of the present invention, stable energy absorption characteristics can be obtained by the buckling stress that acts when the cylindrical body is crushed in the axial direction. In particular, according to the second aspect of the present invention, the fibers are crushed while being peeled off, so that the decrease in stress becomes slow and stable high energy absorption characteristics can be obtained. Moreover, according to the structure of Claim 3, the weakening of the contact surface of mutually adjacent things can be suppressed, and according to the structure of Claim 4, it is effective for the further increase in intensity | strength.

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

  FIG. 1 is a schematic configuration diagram of an automobile frame to which the present invention is applied. This frame is assembled by welding various structural members formed of, for example, an aluminum alloy drawn (extruded) material to each other. The rear end of the frame is joined to the dashboard lower cross member 1 and extends forward. A pair of left and right front side frames 2, a bumper stay 3 coupled to the front ends of both front side frames 2, and a pair of left and right rear side frames 5 coupled to the rear cross member 4 with the front ends thereof extended backward. A pair of left and right side sills 6 extending in the front-rear direction so as to connect the left and right ends of the dashboard lower cross member 1 and the rear cross member 4 and the left and right side sills 6 are connected to each other under the floor of the living room. The middle cross member 7 is provided.

  As shown in FIG. 2, the side sill 6 extending in the longitudinal direction of the vehicle body has a partition wall 11 at an intermediate portion in the vertical direction in the hollow closed cross section of the square tube, and the cross-sectional shape is a Japanese character. A plurality of cylindrical bodies 12 formed of a fiber reinforced resin material (hereinafter referred to as FRP material) reinforced with aramid fibers, carbon fibers, or the like are inserted in an intermediate portion between the portions to which the cross members are connected.

  These cylindrical bodies 12 have their axes in the direction perpendicular to the longitudinal direction of the side sill 6 between the opposing inner surfaces of the left and right side walls 13, 14 of the side sill 6, in other words, in the direction in which a bending load is input during a side collision. It is extended and arranged adjacent to each other in parallel.

  In addition to this, a flat plate 15 made of FRP material is provided on the surface on which the tensile stress acts when a bending load from the outside of the vehicle body is applied to the side sill 6, that is, the outer surface of the wall 14 on the passenger compartment side, for example, double-sided tape. 16 or the like.

  Here, when the load center matches the contact surfaces of the cylinders 12 adjacent to each other, the reinforcement efficiency of the cylinders 12 is reduced, so that the parts of the cylinders 12 adjacent to each other may be bent in the longitudinal direction of the side sill 6 and bent. The centers of the cylindrical bodies 12 may be shifted up and down so as to overlap when viewed from a direction orthogonal to the direction of load application (see dimension A in FIG. 3) (see dimension B in FIG. 3). Moreover, also when it is set as two steps | paragraphs of upper and lower sides, it is good to shift the center of cylindrical bodies 12 about the longitudinal direction of the side sill 6 by the upper stage and the lower stage (refer C dimension in FIG. 3, 4). By arranging the plurality of cylindrical bodies 12 in this way, the local reduction of the buckling stress in the longitudinal direction of the side sill 6 can be minimized.

  According to a conventional side sill composed of only a hollow material of an aluminum alloy, when the bending load from the side is concentrated, the cross section cannot be maintained and the deformation increases locally (see FIG. 5). Then, as indicated by the broken line in FIG. 6, since the stress rapidly decreases and the deformation proceeds, there is a concern that the speed of entering the vehicle interior increases and damage to the passenger increases. According to the present invention, when a load from the side toward the vehicle interior is applied, the bending stress rapidly decreases as shown by the solid line in FIG. 6 due to the compressive stress of the cylindrical body 12. Can be suppressed.

  A chamfer 17 having an appropriate angle is provided on the axial end surface of the cylindrical body 12. As a result, it is possible to reduce the initial load of crushing, suppress an excessive increase in the yield point, and suppress a non-uniform stress distribution by making the cross-sectional shape circular, and the fibers stacked in layers gradually By making it peel, it can suppress that stress falls sharply and can increase the absorbed amount of impact energy.

  The progress of deformation can be controlled by the tensile stress against the bending load from the outside of the vehicle body by the flat plate 15 adhered to the surface of the side sill on the vehicle interior side.

  When the cylindrical body 12 is fixed in the side sill 6, as shown in FIG. 7, a plurality of cylindrical bodies 12 are bonded together to produce a cylinder group G of an appropriate length in advance, For example, holes 18 are formed in advance in places where the cylindrical groups G are to be located at both ends, for example. Note that the diameter of the hole 18 is smaller than the outer diameter of the cylindrical body 12 and slightly larger than the inner diameter.

  On the other hand, a structure in which a short tube 19 of a size that can be fitted to the inner diameter of the cylindrical body 12 is fixed to the surface of the reinforcing flat plate 15 facing the side sill 6 is prepared.

  Then, the cylindrical body group G is inserted into the side sill 6, the mutual alignment between the hole 18 and the corresponding cylindrical body 12 is performed, an adhesive is applied to the short pipe 19, and the cylindrical body 12 is fitted through the hole 18. The flat plate 15 is bonded to the outer surface of the side wall 14 of the side sill 6 on the passenger compartment side. Thereby, the plurality of cylindrical bodies 12 and the flat plate 15 are integrated with the side sill 6.

  As shown in FIG. 8, as a means for fixing the cylindrical body 12 to the side sill 6, it is formed of a synthetic resin material rich in self-lubricating property and elasticity, and cantilevered leaf spring pieces 20 project obliquely on the upper and lower surfaces thereof. A method of holding a plurality of cylindrical bodies 12 with the cylindrical body holder 21 and inserting the cylindrical body holders 21 into the side sill 6 is also conceivable.

  Here, the dimension D between the free ends of the leaf spring pieces 20 of the cylindrical holder 21 is larger than the vertical dimension E of the square pipe constituting the side sill 6, and the cylindrical holder 21 is inserted into the side sill 6. Then, the leaf spring piece 20 is bent to apply a pressing force to the upper and lower walls of the side sill 6, whereby the cylindrical body 12 is positioned in the side sill 6 via the cylindrical body holder 21.

  As shown in FIG. 9, a rack member 23 in which meshing claws 22 having a sawtooth shape in cross-section are fixed to at least one of the upper and lower walls of the side sill 6, and a cantilever plate is attached to the meshing claws 22. The free end of the spring piece 20 can be hooked to prevent it from coming off. In this case, depending on the setting of the direction of inclination of the leaf spring piece 20 and the direction of the inclined surface of the meshing claw 22, the advancement in only one direction is allowed and the backward movement is prohibited.

  The application of the present invention is not limited to the above-described side sill, and can be widely applied to a portion where the deformation characteristics with respect to the bending load are desired to be adjusted as desired.

1 is a schematic perspective view of a vehicle body frame to which the present invention is applied. It is a longitudinal cross-sectional view of the side sill reinforced by this invention. It is sectional drawing which follows the III-III line | wire in FIG. 2 of the side sill reinforced by this invention. It is sectional drawing similar to FIG. 3 which shows another embodiment. It is a top view which shows the aspect of the bending deformation of the conventional side sill. It is a stress-displacement characteristic diagram which compares the conventional thing and the thing of this invention. It is a perspective view which shows one Embodiment of this invention. It is a side view which shows the 2nd Embodiment of this invention. It is a side view which shows the 3rd Embodiment of this invention.

Explanation of symbols

6 Side sill 12 Reinforcing cylinder 13/14 Side wall 15 Reinforcing flat plate

Claims (4)

  A composite structural material characterized in that a reinforcing cylindrical body having an axial line extending in a direction in which a bending load is applied is provided between opposing inner surfaces of side walls of a beam member having a hollow closed section made of a light metal material.   The composite structural material according to claim 1, wherein the reinforcing cylindrical body is formed of a fiber reinforced resin material.   The plurality of reinforcing cylindrical bodies are arranged in parallel, and a part of those adjacent to each other is overlapped when viewed from a direction orthogonal to the longitudinal direction and the direction in which the bending load is applied. The composite structure material according to 2.   The composite structural material according to any one of claims 1 to 3, wherein a reinforcing flat plate is bonded to a surface opposite to a surface to which a bending load is applied.

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