JP2008155709A - Bumper structure for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce crushing remaining of an energy absorption member. <P>SOLUTION: The bumper absorber 18 is formed to a cross section of an approximately U shape, and is crushed to a bumper reinforcement side by bending an upper wall part 18A and a lower wall part 18B at an intermediate part in a vehicle body longitudinal direction. Further, on these upper wall part 18A and lower wall part 18B, an inner notch 20 and an outer notch 22 for restraining front and rear side portions of bending from being superposed in the vehicle body longitudinal direction, are formed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bumper structure for a vehicle.

In a conventional vehicle bumper (see, for example, Patent Document 1), a foamed bumper absorber (energy absorbing member) for protecting a pedestrian is attached to the front side (collision side) of bumper reinforcement.
JP 2004-224106 A

  In the vehicle bumper having the above configuration, the energy absorbing member is formed in a U-shaped cross section so that the remaining crush of the energy absorbing member is reduced. However, the upper and lower pieces of the energy absorbing member are not crushed. For this reason, there is a limit to reducing the remaining uncrushed energy absorbing member as a whole.

  In view of the above facts, an object of the present invention is to obtain a vehicle bumper structure that can reduce the remaining crush of an energy absorbing member.

  A bumper structure for a vehicle according to a first aspect of the present invention includes an upper wall portion and a lower wall portion that are attached to a collision side of a bumper reinforcement of the vehicle and face each other in the vertical direction of the vehicle body. An energy absorbing member that is crushed to the bumper reinforcement side by bending the upper wall portion and the lower wall portion when a load greater than a predetermined value directed toward the side is applied, and the upper wall portion and the lower wall portion are It is characterized by having a polymerization inhibiting means for suppressing overlapping of the upper wall portion and the lower wall portion before and after the bending in the crushing direction when bending.

  In the vehicle bumper structure according to claim 1, when a load of a predetermined value or more directed toward the bumper reinforcement side acts on the energy absorbing member, the upper wall portion and the lower wall portion of the energy absorbing member are bent, thereby absorbing the energy. The member is crushed to the bumper reinforcement side. Here, when the upper wall portion and the lower wall portion are bent, the overlapping in the crushing direction of the portions before and after the bending of the upper wall portion and the lower wall portion is suppressed by the polymerization suppressing means. Therefore, the remaining crush of the energy absorbing member due to this overlap can be reduced.

  A bumper structure for a vehicle according to a second aspect of the present invention is the bumper structure for a vehicle according to the first aspect, wherein the polymerization suppressing means is formed on the bumper reinforcement side of the upper wall portion and the lower wall portion. An inner notch formed on the upper wall portion and the lower wall portion on the opposite side of the bumper reinforcement, and the inner notch and the outer notch are arranged in the longitudinal direction of the bumper reinforcement. It is characterized by being alternately arranged along.

  In the vehicle bumper structure according to claim 2, when the upper wall portion and the lower wall portion are bent, the upper and lower bent portions of the upper wall portion and the lower wall portion are inserted into the inner cutout or the outer cutout. The overlapping of the front and rear portions of the part and the lower wall part is suppressed. Therefore, the polymerization inhibiting means can be made simple.

  A vehicle bumper structure according to a third aspect of the present invention is the vehicle bumper structure according to the second aspect, wherein the inner notch and the outer notch are formed in a triangular shape when viewed from the vehicle body vertical direction. It is a feature.

  In the vehicle bumper structure according to claim 3, the inner notch and the outer notch formed in the upper wall portion and the lower wall portion of the energy absorbing member are formed in a triangular shape when viewed from the vertical direction of the vehicle body. The outer notches are alternately arranged along the longitudinal direction of the bumper reinforcement. For this reason, the shape of the upper wall portion and the lower wall portion is such that a plurality of V-shaped portions are arranged in the longitudinal direction of the bumper reinforcement when viewed from the vertical direction of the vehicle body. Therefore, it is possible to disperse the load toward the bumper reinforcement side acting on the energy absorbing member over a wide range of the energy absorbing member along the longitudinal direction of the bumper reinforcement.

  A bumper structure for a vehicle according to a fourth aspect of the present invention is the bumper structure for a vehicle according to any one of the first to third aspects, wherein the bumper reinforcement is provided on the upper wall portion and the lower wall portion. And the upper wall portion is inclined and arranged to rise toward the bumper reinforcement side, and the lower wall portion is It is arranged to be inclined so as to descend toward the bumper reinforcement side.

  In the vehicle bumper structure according to claim 4, the upper wall portion is inclined so as to rise toward the bumper reinforcement side, and the lower wall portion is inclined so as to descend toward the bumper reinforcement side. Arranged. Therefore, when the energy absorbing member is crushed, it is possible to prevent the vertical wall portion that connects the upper wall portion and the lower wall portion in the vertical direction of the vehicle body from interfering with the upper wall portion and the lower wall portion.

  The bumper structure of the vehicle according to claim 5 is attached to a collision side of the bumper reinforcement of the vehicle, and has an upper wall portion and a lower wall portion facing in the vertical direction of the vehicle body, and directed toward the bumper reinforcement side. An energy absorbing member that is crushed to the bumper reinforcement side by deforming the upper wall portion and the lower wall portion when a load greater than a predetermined value is applied, and provided on the upper wall portion and the lower wall portion, Deformation amount increasing means for increasing the deformation amount of the upper wall portion and the lower wall portion in the collapse direction is characterized.

  In the vehicle bumper structure according to claim 5, when a load greater than a predetermined value directed toward the bumper reinforcement side acts on the energy absorbing member, the upper wall portion and the lower wall portion of the energy absorbing member are deformed, thereby The absorbent member is crushed toward the bumper reinforcement side. Here, when the upper wall portion and the lower wall portion are deformed, the deformation amounts of the upper wall portion and the lower wall portion are increased by the deformation amount increasing means provided on the upper wall portion and the lower wall portion. Therefore, the remaining crush of the energy absorbing member can be reduced.

  As described above, in the vehicle bumper structure according to claim 1 of the present invention, the remaining crush of the energy absorbing member can be reduced.

  In the bumper structure for a vehicle according to claim 2 of the present invention, the polymerization suppression means can be made simple.

  In the bumper structure for a vehicle according to claim 3 of the present invention, the load directed toward the bumper reinforcement acting on the energy absorbing member can be dispersed in a wide range of the energy absorbing member along the longitudinal direction of the bumper reinforcement. It becomes possible.

  In the vehicle bumper structure according to claim 4 of the present invention, when the energy absorbing member is crushed, the vertical wall portion that connects the upper wall portion and the lower wall portion in the vertical direction of the vehicle body interferes with the upper wall portion and the lower wall portion. Can be suppressed.

  In the vehicle bumper structure according to the fifth aspect of the present invention, the remaining crush of the energy absorbing member can be reduced.

  An embodiment of a bumper structure for a vehicle according to the present invention will be described with reference to FIGS. In the figure, the arrow FR indicates the vehicle body front direction, the arrow UP indicates the vehicle body upward direction, and the arrow IN indicates the vehicle width inside direction.

  As shown in FIG. 1, in the present embodiment, a front bumper 12 is disposed along the vehicle width direction at the lower front end of the automobile body 10. The front bumper 12 includes a bumper cover 14 that constitutes the design of the vehicle body 10, and a metal bumper reinforcement 16 (strength member) is provided on the rear side of the vehicle body of the bumper cover 14.

  The bumper reinforcement 16 is formed in a long rectangular tube shape along the vehicle width direction, and is fixed to the lower front end of the vehicle body 10. A plurality (two in this case) of ribs are provided in the bumper reinforcement 16, and the inner space in the bumper reinforcement 16 is divided into three in the vertical direction.

  Shock absorption as an energy absorbing member formed by foaming a resin material (for example, polypropylene, polystyrene, foamed beads) on the collision side (vehicle body front side) of the front wall portion 16A of the bumper reinforcement 16. A bumper absorber 18 is disposed along the vehicle width direction.

  As shown in FIG. 2, the bumper absorber 18 connects the upper wall portion 18A and the lower wall portion 18B facing each other in the vertical direction of the vehicle body and the front end portions of the upper wall portion 18A and the lower wall portion 18B in the vertical direction of the vehicle body. And has a substantially U-shaped cross section that opens toward the rear side of the vehicle body (the bumper reinforcement 16 side). The bumper absorber 18 is attached to the bumper reinforcement 16 by the rear end portions of the upper wall portion 18A and the lower wall portion 18B being locked to the front wall portion 16A of the bumper reinforcement 16.

  As shown in FIG. 1, the upper wall portion 18A is inclined so as to rise toward the rear side of the vehicle body, and the lower wall portion 18B is inclined so as to be lowered toward the rear side of the vehicle body. Yes. Therefore, the upper wall portion 18A and the lower wall portion 18B are arranged in a letter C shape in a side view, and the gap between the upper wall portion 18A and the lower wall portion 18B is closer to the rear side of the vehicle body than the front side of the vehicle body. It has been expanded.

  Furthermore, an inner notch 20 and an outer notch 22 as polymerization restraining means (deformation amount increasing means) are respectively provided in the upper wall portion 18A and the lower wall portion 18B of the bumper absorber 18 in the vehicle width direction (longitudinal direction of the bumper reinforcement 16). Are formed side by side.

  The inner notch 20 is formed from the rear end of the upper wall portion 18A and the lower wall portion 18B toward the front end side of the upper wall portion 18A and the lower wall portion 18B. It is formed into a shape. Further, the outer notch 22 is formed from the front ends of the upper wall portion 18A and the lower wall portion 18B toward the rear end side of the upper wall portion 18A and the lower wall portion 18B. It is formed in a triangular shape.

  The inner notches 20 and the outer notches 22 are alternately arranged along the longitudinal direction (vehicle width direction) of the upper wall portion 18A and the lower wall portion 18B, and the rear ends of the inner notches 20 and the outer notches 22 are rearranged. The end overlaps with the vehicle width direction. Therefore, the shapes of the upper wall portion 18A and the lower wall portion 18B are such that a plurality of V-shaped portions are arranged along the vehicle width direction when viewed from the vehicle body vertical direction (see FIG. 3).

  The vertical wall portion 18C of the bumper absorber 18 is formed in a flat plate shape that is continuous in the longitudinal direction (vehicle width direction), and the vertical wall portion 18C has no cutouts or holes. .

  Here, in the bumper absorber 18 configured as described above, when an impact load of a predetermined value or more directed toward the rear side of the vehicle body (bumper reinforcement 16 side) acts on the vertical wall portion 18C, the upper wall portion 18A and the lower wall portion 18B are It bends at the middle part in the front-rear direction (see FIGS. 4 and 5). At the time of this bending, the upper wall portion 18A is bent and deformed so that the bent portion protrudes upward of the vehicle body, and the lower wall portion 18B is bent and deformed so as to protrude the bent portion downward of the vehicle body. Thereby, the displacement to the vehicle body rear side of the vertical wall part 18C is permitted, and the bumper absorber 18 is crushed to the bumper reinforcement 16 side.

  Next, the operation of this embodiment will be described.

  In the present embodiment, for example, a pedestrian's leg or the like collides with the front side of the bumper cover 14 and an impact load of a predetermined value or more directed toward the rear side of the vehicle body on the vertical wall portion 18C of the bumper absorber 18 via the bumper cover 14 When this occurs, the bumper absorber 18 is crushed toward the bumper reinforcement 16 side by bending the upper wall portion 18A and the lower wall portion 18B of the bumper absorber 18 at an intermediate portion in the vehicle longitudinal direction.

  In addition, when the upper wall portion 18A and the lower wall portion 18B are bent, as shown in FIG. 4B, the portion before the bending of the upper wall portion 18A and the lower wall portion 18B (portion provided with reference numeral 24). 5 enters the inner notch 20 and, as shown in FIG. 5B, the bent portions of the upper wall portion 18A and the lower wall portion 18B (portions provided with reference numeral 26) enter the outer notch 22. For this reason, overlapping of the portions before and after the bending of the upper wall portion 18A and the lower wall portion 18B in the crushing direction (here, the rear direction of the vehicle body) is suppressed, whereby the crushing residue of the bumper absorber 18 is reduced.

  That is, in the bumper absorber having a substantially U-shaped cross section like the bumper absorber 18 according to the present embodiment, when the inner notch 20 and the outer notch 22 of the upper wall portion 18A and the lower wall portion 18B are omitted, FIG. As shown in FIG. 5, when the bumper absorber 18 is crushed, the portions before and after the bending of the upper wall portion 18 </ b> A and the lower wall portion 18 </ b> B overlap in the direction in which the bumper absorber 18 is crushed. For this reason, the remaining crushing allowance b2 of the bumper absorber becomes large (for example, b2 / a2≈20%), and as shown in FIG. 7, the bottom load is generated at an early timing in the FS diagram. End up. That is, since the bumper absorber load F rapidly increases with a small dynamic stroke S of the bumper absorber, the bumper absorber load F has the maximum load F1 defined by the law before obtaining a desired energy absorption amount. It will exceed.

  In order to delay the generation of such a bottomed load, the length c2 of the bumper absorber in the front-rear direction of the vehicle body is set in advance by a length corresponding to the remaining crushing allowance b2 in consideration of the remaining crushing allowance b2 of the bumper absorber. Such measures are necessary. For this reason, the length dimension a2 of the bumper absorber in the longitudinal direction of the vehicle body becomes long, which restricts the length dimension of the bumper cover in the longitudinal direction of the vehicle body, that is, the design of the vehicle.

  In this regard, in the present embodiment, as described above, the overlapping of the front and rear portions of the upper wall portion 18A and the lower wall portion 18B is suppressed, and the remaining crush margins b1 and b1 ′ of the bumper absorber 18 are reduced (for example, , B1 / a1≈b1 ′ / a1≈10%), the length dimension a1 of the bumper absorber 18 in the vehicle body front-rear direction (stroke direction) in a normal state (before impact action) can be set short. Design restrictions can be reduced.

  In addition, in the present embodiment, the inner notch 20 and the outer notch 22 formed in the upper wall portion 18A and the lower wall portion 18B suppress the overlapping of the portions before and after the bending of the upper wall portion 18A and the lower wall portion 18B. The overlap can be suppressed with a simple configuration.

  Further, in the present embodiment, the upper wall portion 18A is disposed so as to be inclined toward the bumper reinforcement 16 side, and the lower wall portion 18B is inclined so as to be lowered toward the bumper reinforcement 16 side. Has been placed. Therefore, when the bumper absorber 18 is crushed, it is possible to prevent the vertical wall portion 18C from interfering with the upper wall portion 18A and the lower wall portion 18B, thereby reducing the remaining crush of the bumper absorber 18.

  Furthermore, in the present embodiment, the vertical wall portion 18C of the bumper absorber 18 is formed in a flat plate shape continuous in the longitudinal direction (vehicle width direction), and no cutouts or holes are formed in the vertical wall portion 18C. Therefore, the load F (dot or linear load, see FIG. 2) input from the pedestrian's leg or the like to the vertical wall 18C can be propagated in the longitudinal direction of the vertical wall 18C (see FIG. 8). In FIG. 8, the vertical walls 18C are not hatched). Therefore, the load drop of the bumper absorber 18 due to the inner notch 20 and the outer notch 22 being formed in the upper wall portion 18A and the lower wall portion 18B can be suppressed.

  In the present embodiment, the upper wall portion 18A and the lower wall portion 18B of the bumper absorber 18 are configured by a plurality of V-shaped portions arranged in the vehicle width direction. For this reason, as shown in FIG. 3, the load input to the vertical wall portion 18C from the pedestrian's leg portion or the like is distributed over a wide range in the vehicle width direction, so that the amount of energy absorption can be increased.

  In the above embodiment, the upper wall portion 18A and the lower wall portion 18B are bent when the bumper absorber 18 is crushed. However, the present invention is not limited to this, and the upper wall portion 18A and the lower wall portion 18B The bumper absorber 18 may be compressed in the crushing direction. Even in this case, since the compression amount (deformation amount) of the upper wall portion 18A and the lower wall portion 18B is increased by the inner cutout 20 and the outer cutout 22, the remaining crush of the bumper absorber 18 can be reduced.

  In the above embodiment, the inner notch 20 and the outer notch 22 are formed in a triangular shape as viewed from the vehicle body vertical direction. However, the present invention is not limited to this, and the shapes of the inner notch 20 and the outer notch 22 are as follows. For example, the inner notch 20 and the outer notch 22 may be formed in an arc shape or a trapezoidal shape as viewed from the vertical direction of the vehicle body.

  Furthermore, in the said embodiment, although it was set as the structure by which the inner side notch 20 and the outer side notch 22 formed in the upper wall part 18A and the lower wall part 18B were used as the superposition | polymerization suppression means (deformation amount increase means), this invention is based on this. Not limited to this, a plurality of through-holes and recesses may be formed in the upper wall portion 18A and the lower wall portion 18B, and these may be used as polymerization suppression means (deformation amount increasing means).

  Moreover, although the said embodiment demonstrated the case where this invention was applied with respect to the front bumper 12 of a vehicle, not only this but this invention is applicable also to the rear bumper of a vehicle.

It is a sectional side view which shows the bumper structure of the vehicle which concerns on embodiment of this invention. 1 is a perspective view of a bumper absorber constituting a bumper structure of a vehicle according to an embodiment of the present invention. It is a top view of the bumper absorber which comprises the bumper structure of the vehicle which concerns on embodiment of this invention. 4A is a cross-sectional view taken along line 4-4 in FIG. 2, and FIG. 4B is a cross-sectional view corresponding to the cross section taken along line 4-4 in FIG. 2 when the bumper absorber is crushed. FIG. 5A is a sectional view taken along line 5-5 in FIG. 2, and FIG. 5B is a sectional view corresponding to the section taken along line 5-5 in FIG. 2 in a state where the bumper absorber is crushed. FIG. 5 is a side cross-sectional view showing a state in which the upper wall portion and the lower wall portion are bent and overlapped in the longitudinal direction of the vehicle body in a U-shaped bumper absorber. It is a diagram which shows the load characteristic of the bumper absorber shown by FIG. It is sectional drawing which shows the partial structure of the bumper absorber which comprises the bumper structure of the vehicle which concerns on embodiment of this invention.

Explanation of symbols

10 Bumper structure of vehicle 16 Bumper reinforcement 18 Bumper absorber (energy absorbing member)
18A Upper wall part 18B Lower wall part 18C Vertical wall part 20 Inner notch (Polymerization suppression means, deformation amount increasing means)
22 Outer notch (Polymerization suppression means, deformation increase means)

Claims (5)

It is attached to a bumper reinforcement side of a vehicle and has an upper wall part and a lower wall part facing in the vertical direction of the vehicle body, and when a load of a predetermined value or more directed toward the bumper reinforcement side is applied An energy absorbing member that is crushed to the bumper reinforcement side by bending the upper wall portion and the lower wall portion;
When the upper wall portion and the lower wall portion are bent, the polymerization suppressing means for suppressing overlapping of the upper wall portion and the lower wall portion before and after the bending in the crushing direction;
Bumper structure of a vehicle having   The polymerization suppressing means is formed on an inner notch formed on the bumper reinforcement side of the upper wall portion and the lower wall portion, and on the opposite side of the bumper reinforcement of the upper wall portion and the lower wall portion. The vehicle bumper structure according to claim 1, further comprising an outer notch, wherein the inner notch and the outer notch are alternately arranged along a longitudinal direction of the bumper reinforcement.   3. The vehicle bumper structure according to claim 2, wherein the inner notch and the outer notch are formed in a triangular shape when viewed from a vertical direction of the vehicle body.   The upper wall portion and the lower wall portion have a vertical wall portion that connects the ends of the lower wall portion opposite to the bumper reinforcement in the vehicle body vertical direction, and the upper wall portion rises toward the bumper reinforcement side. 4. The apparatus according to claim 1, wherein the lower wall portion is disposed to be inclined so as to descend toward the bumper reinforcement side. 5. The bumper structure of the described vehicle. An upper wall portion and a lower wall portion which are attached to a collision side of a bumper reinforcement of a vehicle and which face each other in the vertical direction of the vehicle body, and when the load exceeding a predetermined value is applied toward the bumper reinforcement side, the upper wall An energy absorbing member that is crushed to the bumper reinforcement side by deforming the part and the lower wall part,
Deformation amount increasing means provided on the upper wall portion and the lower wall portion, and increasing the deformation amount of the upper wall portion and the lower wall portion in the crushing direction;
Bumper structure of a vehicle having

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