JP5169249B2 - Energy absorbing member and automobile bumper structure - Google Patents

Description

  The present invention relates to an energy absorbing member provided between a bumper fascia and a bumper reinforcement, and an automobile bumper structure.

Conventionally, as this type of energy absorbing member, one having an approximately M-shaped cross section is known (see Patent Document 1 below). This is because the separation portion where the vertical distance gradually increases from the bumper reinforcement arranged inside the vehicle body toward the front bumper fascia, and the bumper reinforcement on the rear end side from each front end of the separation portion. And a compression portion extending in parallel.
JP 2007-176451 A

  Such an energy absorbing member having an approximately M-shaped cross section is the same as that having an approximately U-shaped cross section. However, when an impact is applied from the front of the vehicle body, the ends of the compression parts positioned at the upper and lower sides (ends on the rear side of the vehicle body) Part) is pressed against the bumper reinforcement and bent to the inside or away from each other and buckles, and the energy absorption stroke is reduced and the shock absorption function cannot be sufficiently exhibited.

  Therefore, an object of the present invention is to improve impact absorption performance as an energy absorbing member.

The present invention is provided between a bumper fascia and a bumper reinforcement, and is integrally formed on a surface facing the bumper reinforcement with a rib extending in the vehicle width direction and at least one side of the rib in the vehicle body vertical direction. The ribs are energy absorbing members each having a concavo-convex portion formed along the vehicle width direction , wherein the rib has a thickness in the vertical direction of the vehicle body that is thin at the front end side of the bumper reinforcement side, The main feature is that it is formed thick on the end side, and the convex portion of the concave and convex portion is a tapered mountain shape protruding toward the bumper reinforcement .

According to the present invention, since the rib is continuously integrated with the concavo-convex portion that suppresses the remaining crush, buckling when compressively deforming can be suppressed.
In addition, since the upper and lower thicknesses are thicker toward the base end side of the rib, the impact load is efficiently distributed vertically and uniformly distributed throughout the energy absorbing member, contributing to improved energy absorption efficiency. can do.

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

  FIG. 1 is a perspective view of an energy absorbing member 1 according to an embodiment of the present invention. FIG. 2 is a perspective view of the energy absorbing member 1 shown in FIG. It is side surface sectional drawing seen from the vehicle body side of the bumper structure provided between the bumper reinforcements 5 located in the vehicle body inside of the fascia 3. FIG.

  The energy absorbing member 1 described above is formed long in the vehicle width direction orthogonal to the paper surface in FIG. 2 and has a generally rectangular parallelepiped shape as a whole, and is made of, for example, a polypropylene foam. The bumper reinforcement 5 is formed long in the vehicle width direction similarly to the energy absorbing member 1 and is formed as a hollow closed cross-section member made of metal, for example, at the front end portion of the front side member 7 extending in the longitudinal direction of the vehicle body, which is a vehicle body skeleton member. Supported. The energy absorbing member 1 is fixed to the front surface 5a of the bumper reinforcement 5 with, for example, an adhesive. The bumper fascia 3 forms a part of the external shape of the front surface of the vehicle body, and is formed of, for example, a resin.

  The energy absorbing member 1 includes ribs 9 extending in the vehicle width direction at the center position in the vertical direction on the surface facing the front surface 5a of the bumper reinforcement 5, that is, the surface on the rear side of the vehicle body. The ribs 9 and the concavo-convex portions 11 and 13 are formed integrally and continuously with each other along the vehicle width direction.

  The rib 9 includes a front end flat surface 9a serving as a front end portion that is fixed so as to be able to contact the front surface 5a of the bumper reinforcement 5, and a side surface portion that is located on the side of the concave and convex portions 11 and 13 on both sides of the vehicle body from the front end flat surface 9a. Inclined surfaces 9b and 9c are provided. The inclined surfaces 9b and 9c are inclined so as to be separated from each other as they move away from the front end flat surface 9a toward the front of the vehicle body. That is, as shown in FIG. 2, the inclined surface 9b on the upper uneven portion 11 side has a higher vertical position on the vehicle front side (left side in FIG. 2), and the inclined surface 9c on the lower uneven portion 13 side is on the vehicle front side. The rib 9 is formed so that its vertical position becomes lower, and therefore the thickness of the rib 9 in the vertical direction of the vehicle body is thin at the front end side on the bumper reinforcement 5 side, and the base end side on the bumper fascia 3 side corresponding to the front side of the vehicle It will be thick.

  The concave and convex portions 11 and 13 are formed with concave portions 11a and 13a and convex portions 11b and 13b along the vehicle width direction. At this time, the leading end portions 11c and 13c of the convex portions 11b and 13b and the leading end of the rib 9 are flat. The front and rear direction positions of the vehicle body 9a are substantially the same with the surface 9a being the same surface. That is, as shown in FIG. 2, when the energy absorbing member 1 is attached to the bumper reinforcement 5, the tip flat surface 9a of the rib 9 and the tip portions 11c and 13c of the convex portions 11b and 13b are both bumper rain. The force 5 is brought into contact with the front surface 5a, and in this contact state, for example, an adhesive is used for adhesive fixing.

  Each of the uneven portions 11 and 13 has a convex mountain shape with the convex portions 11b and 13b, and the tip portions 11c and 13c extend linearly in the vertical direction substantially perpendicular to the tip flat surface 9a. On the other hand, the concave portions 11a and 13a are substantially V-shaped when viewed from the top and bottom of the vehicle body so that the width in the vehicle width direction is gradually narrowed on the bottom side (vehicle body front side) corresponding to the shape of the convex portions 11b and 13b. . In addition, the concave portions 11a and 13a are narrower in the vertical direction on the bottom side due to the inclined surfaces 9b and 9c of the rib 9 described above.

  According to the bumper structure of the automobile provided with the energy absorbing member 1 having such a shape, when the obstacle F collides with the vehicle from the front of the vehicle body, the bumper fascia 3 passes through the energy absorbing member 1 behind the bumper reinforcement 5. A collision load is added to.

  At this time, the energy absorbing member 1 is compressed and deformed, but since the entire tip flat surface 9a of the rib 9 extending in the vehicle width direction is pressed against the front surface 5a of the bumper reinforcement 5, the reaction force at the initial stage of the collision can be maintained high. Since the upper and lower thicknesses of the rib 9 on the front end side of the vehicle body are thicker and wider toward the end, the collision load is efficiently distributed vertically and uniformly distributed throughout the energy absorbing member 1 to thereby improve the energy absorption efficiency. It can contribute to improvement.

  At this time, the rib 9 is continuously integrated with the upper and lower concavo-convex portions 11 and 13, and further, combined with the above-described divergent shape, can effectively suppress buckling, and stable energy absorption. It becomes possible. Moreover, by providing the concavo-convex portions 11 and 13, it is possible to reduce the portion that remains crushed and to obtain a more efficient energy absorption effect.

  Further, the upper and lower sides of the rib 9 are inclined surfaces 9b and 9c that are inclined with respect to the horizontal plane, so that the thickness of the rib 9 continuously changes from the distal end to the proximal end, thereby absorbing energy. The efficiency is further improved, and the moldability is improved in combination with the shapes of the uneven portions 11 and 13.

  Furthermore, since the front end flat surface 9a of the rib 9 and the front end portions 11c and 13c of the convex portions 11b and 13b in the concavo-convex portions 11 and 13 are the same surface, the front end flat surface 9a and the front end portion 11c are the same surface. , 13c are in contact with the front surface 5a of the bumper reinforcement 5, so that the contact area can be increased and the impact load can be more stably received.

  Further, by providing the above-described uneven portions 11 and 13 on both the upper and lower sides of the rib 9, the energy absorption efficiency is further improved.

  Then, by adopting such an energy absorbing member 1 in the bumper structure of an automobile, it is possible to suppress the influence on, for example, the passenger compartment inside the vehicle body at the time of a vehicle collision.

  In addition, the fragments generated by the collapse of the rib 9 and the convex portions 11b and 13b at the time of impact absorption can enter the concave portions 11a and 13a and escape.

  FIG. 3A is a reaction force characteristic diagram when a collision experiment using an actual vehicle is performed using the energy absorbing member 1 in which each part size is set as shown in FIG. 4, and FIG. 3B is a comparative example. It is a reaction force characteristic view by a U-shaped energy absorption member. 4 has a length A in the longitudinal direction of the vehicle body = 80 mm, a thickness B in the vertical direction of the vehicle body of 40 mm, and the height of the ribs 9 (protrusions 11b and 13b) (depths of the recesses 11a and 13a). S) C = 14.4 mm, and an inclination angle D = 45 ° with respect to the horizontal plane of the inclined surfaces 9b and 9c.

  According to this, as shown to Fig.3 (a), in this embodiment, it is that the collision initial reaction force is larger than the comparative example of FIG.3 (b), and the subsequent reaction force is maintaining the high state. Recognize. This means that the rib 9 and the convex portions 11b and 13b are efficiently compressed and deformed.

It is a perspective view of the energy absorption member which shows one Embodiment of this invention. It is side surface sectional drawing seen from the vehicle body side of the bumper structure to which the energy absorption member of FIG. 1 is applied. (A) is a reaction force characteristic diagram when a collision test using an actual vehicle is performed using an energy absorbing member that defines the dimensions of each part shown in FIG. 4, and (b) is a U-shaped energy absorbing member as a comparative example. It is a reaction force characteristic diagram. It is a shape figure which shows each part dimension of the energy absorption member corresponding to the reaction force characteristic view of Fig.3 (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Energy absorption member 3 Bumper fascia 5 Bumper reinforcement 9 Rib 9a Flat end surface of rib (tip part of rib)
9b, 9c Rib inclined surface (side surface of rib)
11, 13 Uneven portion 11a, 13a Uneven portion of uneven portion 11b, 13b Uneven portion of protruding portion 11c, 13c End portion of protruding portion

Claims (5)

Provided between a bumper fascia located outside the vehicle body and a bumper reinforcement located inside the vehicle body of the bumper fascia, a rib extending in the vehicle width direction is provided on a surface facing the bumper reinforcement, and the rib An energy absorbing member comprising a concavo-convex portion formed along the vehicle width direction while being continuously integrated with at least one side of the vehicle body vertical direction ,
The rib is formed with a thickness in a vertical direction of the vehicle body that is thin on a distal end side on the bumper reinforcement side and thick on a proximal end side on the bumper fascia side,
The convex part of the said uneven part is a taper mountain shape which protrudes toward the said bumper reinforcement, The energy absorption member characterized by the above-mentioned. The rib has a front end portion that can contact the front surface of the bumper reinforcement, and a side surface portion that extends from the front end portion toward the bottom of the concave portion of the uneven portion, and the side surface portion is inclined with respect to a horizontal plane. by the inclined surface, the energy absorbing member according to claim 1, characterized in that changing the vertical direction of the vehicle body in the thickness of the rib. 3. The energy absorbing member according to claim 1, wherein a leading end portion of the rib and a leading end portion of the convex portion of the concavo-convex portion are flush with each other. The energy absorbing member according to any one of claims 1 to 3 , wherein the uneven portions are provided on both sides of the rib in a vertical direction of the vehicle body. An automobile bumper structure using the energy absorbing member according to any one of claims 1 to 4 .

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