JP2006205806A - Impact-absorbing structure for fender section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact-absorbing structure for a fender section capable of attaining energy absorbing characteristics with sustainable reaction even after the latter of deformation. <P>SOLUTION: An inside vertical wall section 10B of a front fender panel 10 is mounted on an apron upper member 14 through an energy absorbing bracket 18 of which cross section is of rough Ω shape. A total of side lengths of an upper section 26 of the bracket 18 is different from that of a lower section 28, therefore ironing deformation which causes a knot to sequentially move can be obtained in the course of deformation process, thus increasing a load for the latter of deformation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fender portion impact absorbing structure in which a vertical wall portion disposed inside an upper end portion of a fender panel is attached to a body panel via an energy absorbing bracket.

  Conventionally, as part of pedestrian protection measures, it has been proposed to attach the inner vertical wall portion of the front fender panel to the top wall portion of the apron upper member via an energy absorbing bracket (see the following patent document).

  For example, Patent Document 1 below discloses a bracket that has a generally hat shape in a side view. The inner vertical wall portion of the front fender panel is fixed to the upper surface of the bracket, and the lower end portions of a pair of front and rear leg portions are fixed to the apron upper member. Further, a bent portion that is bent inward of the bracket is formed at the intermediate portion in the height direction of the leg portion disposed on the rear side.

According to the above configuration, when the colliding body collides with the parting part between the front fender panel and the hood panel from the upper side, the bracket is further bent inward from the bent portion, thereby absorbing energy at the time of the collision. . Further, since the bracket is arranged in the vehicle front-rear direction, when the bracket is deformed, it does not swell outward in the vehicle width direction, and there is no need to secure a space in that direction. Furthermore, rigidity in the vehicle width direction can be secured, and the installation accuracy of the parting part between the front fender panel and the hood panel is improved.
JP 2003-118639 A Japanese Patent Laid-Open No. 2002-178953

  However, in the case of the above prior art bracket, since the cross-sectional shape is open and the upper side is not supported on the lower side, when a collision load is applied from the upper side of the vehicle, the ridge line of the shape is directly moved to the lower side of the bracket. After the plastic deformation so as to be lowered, the entire bracket is plastically deformed so as to fall in the vehicle front-rear direction. For this reason, the reaction force in the second half of the deformation is low, and energy absorption at the time of collision cannot be performed continuously.

  In view of the above facts, the present invention has an object to obtain a fender shock absorbing structure capable of obtaining an energy absorption characteristic in which the reaction force is sustained even in the latter half of deformation.

  The fender portion shock absorbing structure according to the present invention is a fender portion shock absorbing structure in which a vertical wall portion disposed inside an upper end portion of a fender panel is attached to a body panel via an energy absorbing bracket. In the bracket, the upper and lower sides of the polygon formed by the bracket and the body panel are vertically asymmetrical, and the upper side length sum and the lower side length sum are not equal. The feature is that the dimensions are set.

  A fender impact absorbing structure according to a second aspect of the present invention is characterized in that, in the first aspect of the present invention, the lower part of the bracket has a narrowed shape with respect to the upper part.

  According to a third aspect of the present invention, in the fender portion shock absorbing structure according to the first or second aspect, the lower plate width and the upper plate width of the bracket are changed. Yes.

  According to the first aspect of the present invention, the vertical wall portion disposed inside the upper end portion of the fender panel is attached to the body panel via the energy absorbing bracket.

  When the collision body collides with the vertical wall portion of the fender panel from above the vehicle, the collision load is input to the bracket through the vertical wall portion and then transmitted to the body panel. In this process, the energy absorbing bracket is plastically deformed (collapsed) in the vehicle vertical direction, so that energy is absorbed at the time of collision.

  Here, in the present invention, the upper part and the lower part of the polygon formed by the bracket and the body panel are asymmetrical in the vertical direction, and the sum of the upper side length and the lower side length of the polygon are formed. Since the dimensions are set so that the sum is not equal, the following effects are obtained.

  In other words, if the upper and lower parts of the polygon are vertically symmetric, and the dimensions are set so that the upper side length sum and the lower side length sum are equal, the upper part of the bracket is deformed to the lower side ( The deformation of the bracket is completed by simply performing plastic deformation so that the polygonal ridgeline part (the part that is the vertex of the polygon and becomes the node of the bracket) descends to the vehicle lower side. End up. Therefore, a reaction force due to the deformation of the ridge line portion is obtained in the first half of the deformation of the bracket, but a reaction force for energy absorption is greatly reduced in the second half of the deformation of the bracket.

  On the other hand, in the present invention, since the above configuration is adopted, in order for the upper part of the bracket to be deformed to the lower side (in order to come down), the nodes that are plastic deformation sites move sequentially and sequentially. It is necessary to make such a deformation (ie, ironing deformation). This squeezing deformation generates a reaction force in the latter half of the deformation of the bracket. Therefore, according to the present invention, it is possible to obtain an energy absorption characteristic in which the reaction force (F of the FS characteristic) continues even in the latter half of the deformation of the bracket.

  According to the second aspect of the present invention, since the lower portion of the bracket has a shape that is narrowed with respect to the upper portion, the shape formed by the bracket and the body panel can be stably deformed such as a hexagon. The shape can be made.

  In addition, when the lower part of the bracket is shaped to be constricted with respect to the upper part, the boundary part between the upper part and the lower part protrudes outward with deformation. Therefore, it is possible to avoid the phenomenon of mutual interference due to the brackets deforming inward during the deformation.

  According to the third aspect of the present invention, since the lower plate width and the upper plate width of the bracket are changed, for example, the reaction force can be gradually changed in the second half of the deformation. In other words, when there are a small plate width and a large plate width, a larger plate width requires more energy to deform. Therefore, the energy absorption characteristics can be arbitrarily adjusted by changing the lower plate width and the upper plate width of the bracket.

  As described above, in the fender portion impact absorbing structure according to the first aspect of the present invention, the energy absorbing bracket is such that the upper and lower portions of the polygon formed by the bracket and the body panel are vertically asymmetrical. Since the dimension is set so that the upper side length sum and the lower side length sum of the polygon are not equal, the bracket can be squeezed and deformed when the impact load is applied. Even in the second half of the deformation of the bracket, there is an excellent effect that an energy absorption characteristic that the reaction force is sustained is obtained.

  The fender part shock absorbing structure according to the second aspect of the present invention is the fender part shock absorbing structure according to the first aspect of the present invention. It is easy to make and it is possible to prevent the brackets from interfering with each other during the deformation, and as a result, it has an excellent effect that the targeted energy absorption characteristics can be easily realized.

  In the fender part impact absorbing structure according to the third aspect of the present invention, in the invention according to the first or second aspect, the lower plate width and the upper plate width of the bracket are changed. It is also possible to gradually change the reaction force, and it has an excellent effect that the energy absorption characteristics can be easily tuned.

  Hereinafter, several embodiments of the fender portion impact absorbing structure according to the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow OUT indicates the vehicle width direction outer side.

  FIG. 1 shows a side view of the fender portion shock absorbing structure according to the present embodiment as viewed from the inside of the engine room. Further, FIG. 2 shows a longitudinal sectional view of the fender portion impact absorbing structure as viewed from the front side of the vehicle when cut along the vehicle width direction.

  As shown in these drawings, a front fender panel 10 is disposed on the side surface of the front portion of the vehicle body. The front fender panel 10 covers the upper side of the front wheel and constitutes an outer vertical wall portion 10A that constitutes a design surface, and the front fender panel 10 is suspended from the upper end portion of the outer vertical wall portion 10A and bent (extended) horizontally to the engine room 12 side. And the inner vertical wall portion 10B.

  An apron upper member 14 is disposed below the inner vertical wall portion 10B of the front fender panel 10. The apron upper member 14 has a substantially U-shaped cross-section opened downward, and is disposed with the vehicle front-rear direction as the longitudinal direction.

  Further, a hood 16 that opens and closes the engine room 12 is disposed between the upper ends of the inner vertical wall portions 10B of the pair of left and right front fender panels 10. A sealing material (not shown) made of an elastic material (rubber) is disposed on the lower edge side of both end portions in the width direction of the hood 16 and elastically deformed to the vertical portion 10B1 of the inner vertical wall portion 10B of the front fender panel 10. It comes to be pressed in the state.

  The inner vertical wall portion 10 </ b> B of the front fender panel 10 described above is attached to the apron upper member 14 via a pair of front and rear energy absorbing brackets 18.

  More specifically, as shown in FIGS. 3 and 4, the energy absorption bracket 18 has a substantially Ω shape in a side view, and includes an upper portion 26 and a lower portion 28. The upper portion 26 is bent and suspended in a “C” shape at a predetermined inclination angle from the front and rear ends of the top wall portion 26A arranged in parallel with the top wall portion 14A of the apron upper member 14 and the top wall portion 26A. It consists of three surfaces with a pair of front and rear upper inclined portions 26B. On the other hand, the lower portion 28 includes a pair of front and rear lower inclined portions 28A that are bent and suspended in a reverse “C” shape at a predetermined inclination angle from the pair of upper inclined portions 26B constituting the upper portion 26 toward the inside of the cross section. Each of the lower inclined portions 28A is composed of four surfaces including a pair of front and rear mounting leg portions 28B bent in directions away from each other. Therefore, when the state in which the energy absorbing bracket 18 is assembled to the top wall portion 14A of the apron upper member 14 is viewed from the side, it has a hexagonal shape.

  A pair of mounting legs 28B of the energy absorbing bracket 18 having the above structure is fixed (spot welded) to the top wall 14A of the apron upper member 14. Moreover, the bolt insertion hole 20 (refer FIG. 3) is formed in the top wall part 26A of the energy absorption bracket 18, and the weld nut 22 (refer FIG. 1) is welded beforehand by the back surface side. Then, with the horizontal portion 10B2 of the inner vertical wall portion 10B of the front fender panel 10 placed on the upper surface of the top wall portion 26A of the energy absorbing bracket 18, the bolt 24 is inserted from above the horizontal portion 10B2. The inner vertical wall portion 10B of the front fender panel 10 is attached to the top wall portion 14A of the apron upper member 14 via the energy absorbing bracket 18 by being screwed to the weld nut 22. Note that the weld nut 22 is not necessarily used, and a normal nut may be used.

  Here, as shown in FIG. 4, the energy absorbing bracket 18 described above is formed in a vertically asymmetric shape (and a symmetrical shape). More specifically, when the length of the upper inclined portion 26B constituting the upper portion 26 of the energy absorbing bracket 18 is A and the length of the lower inclined portion 28A constituting the lower portion 28 of the energy absorbing bracket 18 is B, A> B is set. Incidentally, the length X of the top wall portion 26A constituting the upper portion 26 and the length Y of the distance (gap) between the pair of mounting legs 28B are set to be the same (X = Y). That is, the dimension is set so that the sum of the side lengths (= 2 × A + X) of the upper portion 26 and the sum of the side lengths (= 2 × B + Y) of the lower portion 28 of the energy absorbing bracket 18 of the present embodiment are not equal. Has been made. In this embodiment, the dimension is set to X = Y. However, X = Y is not necessarily required, and the side length sum of the upper part 26 and the side length sum of the lower part 28 are set to be different. Just do it.

  The energy absorbing bracket 18 has a shape in which the lower portion 28 is narrowed with respect to the upper portion 26.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 2, when a collision body 32 such as a pedestrian collides with a parting portion 34 between the front fender panel 10 and the hood 16 from the upper side of the vehicle, the collision load F at that time is applied to the inner vertical wall portion 10. Then, the energy is input to the energy absorption bracket 18 and then transmitted to the apron upper member 14. In this process, the energy absorbing bracket 18 is plastically deformed (collapsed) in the vertical direction of the vehicle, so that energy is absorbed during the collision.

  Here, in this embodiment, the hexagonal upper part 26 and the lower part 28 formed by the energy absorption bracket 18 and the top wall part 14A of the apron upper member 14 are asymmetric in the vertical direction. In addition, since the dimension is set so that the side length sum of the hexagonal upper portion 26 and the side length sum of the lower portion 28 are not equal, the following effects are obtained.

  That is, as shown in FIG. 6 as a comparative example, the hexagonal upper part 36 and the lower part 38 are vertically symmetrical, and the side length sum (= 2 × C + X) of the upper part 36 and the side length sum of the lower part 38 ( = 2 × C + Y), in the case of the energy absorbing bracket 40 that is sized (X = Y), when the upper part 36 of the energy absorbing bracket 40 is deformed (collapsed) toward the lower part 38 side, The deformation of the energy absorption bracket 40 can be achieved simply by performing plastic deformation so that the square ridge line portion (the apex of the hexagon and the node of the energy absorption bracket 40; the point Q) descends to the vehicle lower side as it is. It ends. Therefore, as shown in FIG. 7, a reaction force (F) due to the deformation of the ridge portion is obtained in the first half of the deformation of the energy absorption bracket 40, but a reaction force (F) for the energy absorption in the second half of the deformation of the energy absorption bracket 40. ) Cannot be obtained sufficiently.

  In contrast, since the fender shock absorbing structure according to the present embodiment employs the above configuration, as shown in FIG. 4, in order for the upper portion 26 of the energy absorbing bracket 18 to be deformed toward the lower portion 28 ( In order to come down), the deformation (that is, the bending deformation is continuously within the side length A of the upper inclined portion 26B) such that the nodes (points R) that become the plastic deformation sites sequentially move continuously. The ironing deformation that occurs) needs to be made. That is, the node R point before the deformation (solid line) has moved to the position r1 after the deformation (one-dot chain line), and the node R point in the middle of the deformation (the two-dot chain line) has moved to the position r2 after the deformation. ing. This ironing deformation generates a reaction force (F) in the latter half of the deformation of the energy absorbing bracket 18, as shown in FIG. Therefore, according to the present embodiment, an energy absorption characteristic is obtained such that the reaction force (F) continues even in the latter half of the deformation of the energy absorption bracket 18.

  Note that f (load) and s (displacement) of the FS characteristic are determined so that optimum energy absorption is realized. s is determined by the absolute value of the difference between B and the distance from the top wall portion 14A of the apron upper member 14 to the top wall portion 26A of the upper portion 26 of the energy absorption bracket 18, and f is determined by the shape and thickness of the energy absorption bracket 18 and the like. Determined.

  Further, in the fender portion shock absorbing structure according to the present embodiment, the lower portion 28 of the energy absorbing bracket 18 has a shape narrowed with respect to the upper portion 26, so that the top wall of the energy absorbing bracket 18 and the apron upper member 14. The shape formed by the portion 14A can be a shape that can be stably deformed such as a hexagon. That is, it is possible to easily manufacture an energy absorbing bracket having a shape that stably deforms. Further, when the lower portion 28 of the energy absorbing bracket 18 is shaped so as to be constricted with respect to the upper portion 26, the boundary portion (node R point) between the upper portion 26 and the lower portion 28 protrudes outward with deformation. Therefore, it is possible to avoid the phenomenon of mutual interference due to the energy absorbing bracket 18 being deformed inward during the deformation. By avoiding such mutual interference, it is possible to prevent the energy absorption characteristics from changing unexpectedly. As a result, according to the present embodiment, the targeted energy absorption characteristics can be easily realized by the energy absorption bracket 18.

[Supplementary explanation of the embodiment]
In the present embodiment described above, the energy absorbing bracket 18 having a dimension setting in which the sum of the side lengths of the upper portion 26 is larger than the sum of the side lengths of the lower portion 28 is used, but the present invention is not limited to this and is shown in FIGS. As described above, even when the energy absorbing bracket 54 having a dimension setting is used, the side length D of the upper inclined portion 50A constituting the upper portion 50 is shorter than the side length E of the lower inclined portion 52A of the lower portion 52 (D <E). Good. Even in this case, the same operation and effect as in the present embodiment can be obtained.

  Moreover, in this embodiment mentioned above, although the energy absorption bracket 18 by which the board width of each part was set identically was used, as shown in FIG.10 and FIG.11 not only this but the upper part which is a deformation | transformation part. The plate width gradually increases from F to G (F <G) (or conversely decreases gradually) from the upper edge of 60 upper inclined portion 60A to the lower edge of lower inclined portion 62A of lower portion 62. You may use the energy absorption bracket 64 of the structure which goes.

  According to this configuration, since the plate width of the lower portion 62 of the energy absorbing bracket 64 is set to be larger than the plate width of the upper portion 60, as shown in FIG. Can continue. In other words, when there are a small plate width and a large plate width, a larger plate width requires more energy to deform. Accordingly, by setting the plate width as described above, as shown in FIG. 11, the deformation on the lower 62 side becomes dominant in the first half of the deformation, and the reaction force increases. In the second half of the deformation, the deformation on the upper 60 side is increased. Since it becomes superior, an energy absorption characteristic in which the reaction force rises slowly is obtained. In other words, the energy absorption characteristics can be arbitrarily adjusted by adjusting the plate width between the upper portion 60 and the lower portion 62 of the energy absorption bracket 64. As a result, according to the energy absorption bracket 64, the energy absorption characteristics can be easily tuned.

  In addition, as described above, it is not always necessary to gradually increase (gradually change) the plate width from F to G in the upper portion 60 and the lower portion 62 as in the above-described configuration. For example, the width may be changed stepwise. Then, only the upper side may be gradually deformed, and the lower side may have a constant width.

  Further, the tuning of the energy absorption characteristics as described above can be performed not only by changing the plate width of the energy absorbing bracket but also by changing the plate thickness, forming a bead, or the like.

  Further, in the present embodiment described above, as shown in FIG. 12A, the energy absorbing bracket 18 is arranged along the vehicle front-rear direction. However, the present invention is not limited to this, and FIG. As shown, the energy absorption bracket 18 may be arranged along the vehicle width direction.

  Further, in the above-described embodiment, the energy absorbing bracket 18 having a substantially Ω shape (inside the hexagonal shape) is used in a side view. However, the present invention is not limited thereto, and a polygon other than a hexagon may be employed. .

It is the side view which looked at the fender part shock absorption structure concerning this embodiment from the engine room side. It is a longitudinal cross-sectional view which follows the 2-2 line of FIG. 1 which shows the fender part impact absorption structure shown by FIG. 1 seeing from the vehicle front side. It is a perspective view of the energy absorption bracket shown by FIG. It is a side view which shows the mode before and behind a deformation | transformation of the energy absorption bracket shown by FIG. It is a graph which shows the FS characteristic at the time of using the fender part impact absorption structure concerning this embodiment. It is a side view which shows the mode before and behind a deformation | transformation of the energy absorption bracket as a comparison for demonstrating the effect of the energy absorption bracket shown by FIG. It is a graph which shows the FS characteristic at the time of using the energy absorption bracket shown by FIG. It is a perspective view which shows the energy absorption bracket which concerns on a 1st modification. It is a side view which shows the mode before and behind a deformation | transformation of the energy absorption bracket shown by FIG. It is a perspective view which shows the energy absorption bracket which concerns on a 2nd modification. It is a graph which shows the FS characteristic at the time of using the energy absorption bracket shown by FIG. It is a perspective view which shows the 3rd modification which changed the way of arrangement | positioning of an energy absorption bracket.

Explanation of symbols

10 Front fender panel 10B Inner vertical wall 14 Apron upper member (body panel)
18 energy absorption bracket 26 upper part 28 lower part 50 upper part 52 lower part 54 energy absorption bracket 60 upper part 62 lower part 64 energy absorption bracket

Claims (3)

A fender part shock absorbing structure in which a vertical wall part arranged inside the upper end part of a fender panel is attached to a body panel via a bracket for energy absorption,
The bracket is dimensioned so that the upper and lower sides of the polygon formed by the bracket and the body panel are asymmetrical in the vertical direction, and the upper side sum and the lower side sum are not equal. Has been made,
A fender shock absorbing structure characterized by that. The lower part of the bracket has a narrowed shape with respect to the upper part,
The fender portion shock absorbing structure according to claim 1. The lower plate width and the upper plate width of the bracket were changed,
The fender part impact absorption structure according to claim 1 or 2, wherein

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