WO2009056939A2

WO2009056939A2 - Vehicle bumper structure

Info

Publication number: WO2009056939A2
Application number: PCT/IB2008/002858
Authority: WO
Inventors: Soshi Mitsuyama; Takahisa Shiraoka
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2007-10-31
Filing date: 2008-10-28
Publication date: 2009-05-07
Also published as: WO2009056939A3; JP2009107536A

Abstract

Upper and lower wall portions (16A, 16B) of a bumper absorber (16) are sloped so as to be apart more from each other toward the rear of a vehicle body in order to enhance the efficiency of forming the bumper absorber (16) through injection-molding. Therefore, if a load directed toward the rear of the vehicle body is applied to a vertical wall portion (16C) of the bumper absorber (16), component forces that proceed in opposite directions are applied to opening-side end portions of the bumper absorber (16). Therefore, the opening-side end portions of the bumper absorber (16) attempt to be apart more from each other due to these component forces. However, with a vehicle bumper structure according to the invention, spreading apart of the end portions is prevented by projections (18, 20) formed on a front wall portion (14C) of the bumper reinforcement (14).

Description

VEHICLE BUMPER STRUCTURE

BACKGROUND OF THE INVENTION

1. Field of the Invention [0001] The invention relates to a vehicle bumper structure.

2. Description of the Related Art

[0002] In existing vehicle bumper structures, a resin energy absorber is fitted to an impact energy reception-side face of a beam (bumper reinforcement) as described in, for example, Japanese Unexamined Patent Application Publication No. 2005-502521. The energy absorber includes a main body, and a frame that is fitted to the main body at a portion that faces the beam. A U-shaped flange and a finger that are provided at an upper end portion of the frame hold an upper end portion of the bumper reinforcement from above, and a U-shaped flange and a finger that are provided at a lower end portion of the frame hold a lower end portion of the bumper reinforcement from below. In this way, the energy absorber is fitted to the beam.

[0003] Examples of the above-described resin energy absorber include an energy absorber that is formed into a shape having a substantially U-shaped cross-section and that is fitted at its opening-side end portions to an impact energy reception-side face of a bumper reinforcement by clips or hooks. Because such energy absorber is simple in shape, a molding die having a simple structure may be used, which makes it possible to produce the energy absorber at low cost.

[0004] However, in the above-described energy absorber that has a substantially U-shaped cross-section, if, for example, the clip breaks due to an impact load applied to the energy absorber, the opening-side end portions of the energy absorber may spread apart (the distance between the opening-side end portions of the energy absorber may increase) in the vehicle-height direction, which may arise a possibility that the energy absorber does not deform in a prescribed manner. SUMMARY OF THE INVENTION

[0005] The invention provides a vehicle bumper structure with which an energy absorber that opens toward a bumper reinforcement is deformed in a prescribed manner.

[0006] A first aspect of the invention relates to a vehicle bumper structure which includes: an energy absorber that is fitted to an impact energy reception-side face of a bumper reinforcement for a vehicle, and that opens toward the bumper reinforcement; and a spreading apart prevention portion provided to the bumper reinforcement to prevent spreading apart of opening-side end portions of the energy absorber when the energy absorber deforms due to a load that is directed tow the bumper reinforcement. [0007] The "impact energy reception-side face" means a "front face in the longitudinal direction of a vehicle body" when the bumper reinforcement is included in a vehicle front bumper, and means a "rear face in the longitudinal direction of the vehicle body" when the bumper reinforcement is included in a vehicle rear bumper.

[0008] In the vehicle bumper structure according to the aspect described above, the energy absorber that opens toward the bumper reinforcement is fitted to the impact energy reception-side face of the bumper reinforcement. When the energy absorber deforms due to a load directed to the bumper reinforcement, spreading apart of the opening-side end portions of the energy absorber in the vehicle-height direction is prevented by the spreading apart prevention portion that is provided to the impact energy reception-side face of the, bumper reinforcement. Thus, it is possible to deform the energy absorber in a prescribed manner.

[0009] In the vehicle bumper structure according to the aspect described above, the spreading apart prevention portion may include an upper spreading apart prevention portion and a lower spreading apart prevention portion, the upper spreading apart prevention portion may be formed at a position above the energy absorber in the vehicle-height direction, and extend in the longitudinal direction of the bumper reinforcement, and the lower spreading apart prevention portion may be formed at a position below the energy absorber in the vehicle-height direction, and extend in the longitudinal direction of the bumper reinforcement. [0010] With this vehicle bumper structure, when the energy absorber deforms due to a load directed to the bumper reinforcement, spreading apart of the opening-side end portions is suppressed by the upper spreading apart prevention portion and the lower spreading apart prevention portion that are provided above and below the energy absorber in:, the vehicle-height direction, respectively. Because the upper spreading apart prevention portion and the lower spreading apart prevention portion extend in the longitudinal direction of the bumper reinforcement, it is possible to prevent spreading apart of the opening-side end portions of the energy absorber in a wide range along the longitudinal direction of the bumper reinforcement. [0011] In the vehicle bumper structure according to the aspect described above, the opening-side end portions of the energy absorber may contact the spreading apart prevention portion, whereby spreading apart of the opening-side end portions is prevented.

[0012] In the vehicle bumper structure according to the aspect described above, when the energy absorber deforms due to a load directed to the bumper reinforcement, the opening-side end portions of the energy absorber contact the spreading apart prevention portion, whereby spreading apart of the opening-side end portions of the energy absorber is suppressed. Because a compressive load is applied from the spreading apart prevention portion to the energy absorber, it is possible to suppress breakage of the energy absorber efficiently as compared with the case where a shearing load is applied to the energy absorber. When the spreading apart prevention portion extends in the longitudinal direction of the bumper reinforcement, a compressive load that is applied between the spreading apart prevention portion and the energy absorber is dispersed in a wide range along the longitudinal direction of the bumper reinforcement. Therefore, it is possible to more efficiently suppress breakage of the energy absorber.

[0013] In the vehicle bumper structure according to the aspect of the invention described above, the opening-side end portions of the energy absorber may be held by the spreading apart prevention portion, whereby the energy absorber is fitted to the bumper reinforcement. [0014] In this vehicle bumper structure, the opening-side end portions of the energy absorber is held by the spreading apart prevention portion, whereby the energy absorber is fitted to the bumper reinforcement. Therefore, an additional component (component that is separate from the energy absorber and the bumper reinforcement) used to fit the energy absorber to the bumper reinforcement need not be provided, which reduces the number of components.

[0015] In the vehicle bumper structure according to the aspect of the invention described above, the spreading apart prevention portion may be formed of a projection that projects from the impact energy reception-side face of the bumper reinforcement toward the energy absorber.

[0016] In this vehicle bumper structure, spreading apart of the opening-side end portions of the energy absorber is prevented by the projection that projects from the impact energy reception-side face of the bumper reinforcement toward the energy absorber. Therefore, spreading apart of the opening-side end portions of the energy absorber is prevented with a simple structure.

[0017] In the vehicle bumper structure according to the aspect of the invention described above, the energy absorber may include an upper wall portion and a lower wall portion that are sloped so as to be apart more from each other toward the bumper reinforcement and a vertical wall portion that connects the upper wall portion and the lower wall portion to each other, the upper spreading apart prevention portion and the lower spreading apart prevention portion may be formed integrally with the bumper reinforcement, and a bottom face of the upper spreading apart prevention portion may contact an opening-side end portion of the upper wall portion, and a top face of the lower spreading apart prevention portion may contact an opening-side end portion of the lower wall portion.

[0018] In the vehicle bumper structure according to the aspect of the invention described above, the energy absorber may be formed of an upper wall portion and a lower wall portion that are sloped so as to be apart more from each other toward the bumper reinforcement and a vertical wall portion that connects the upper wall portion and the lower wall portion to each other, the upper spreading apart prevention portion and the lower spreading apart prevention portion may be attached to the bumper reinforcement in such a manner that the upper spreading apart prevention portion and the lower spreading apart prevention portion are immovable relative to the bumper reinforcement, and a bottom face of the upper spreading apart prevention portion may contact an opening-side end portion of the upper wall portion, and a top face of the lower spreading apart prevention portion may contact an opening-side end portion of the lower wall portion.

[0019] In the vehicle bumper structure according to the aspect of the invention described above, the energy absorber may be formed of an upper wall portion and a lower wall portion that are sloped so as to be apart more from each other toward the bumper reinforcement and a vertical wall portion that connects the upper wall portion and the lower wall portion to each other, and the spreading apart prevention portion may be formed of an upper groove into which an opening-side end portion of the upper wall portion is fitted, and a lower groove into which an opening-side end portion of the lower wall portion is fitted.

[0020] In the vehicle bumper structure according to the aspect of the invention described above, an upper flange portion that extends upward in the vehicle-height direction may be formed at the opening-side end portion of the upper wall portion, and a lower flange portion that extends downward in the vehicle-height direction may be formed at the opening-side end portion of the lower wall portion. The upper spreading apart prevention portion may include an upper horizontal portion that extends from the impact energy reception-side face of the bumper reinforcement outward in the longitudinal direction of a vehicle body and an upper vertical portion that extends from a tip of the upper horizontal portion downward in the vehicle-height direction, and the lower spreading apart prevention portion may include a lower horizontal portion that extends from the impact energy reception-side face of the bumper reinforcement outward in the longitudinal direction of the vehicle body and a lower vertical portion that extends from a tip of the lower horizontal portion upward in the vehicle-height direction. When the energy absorber is fitted to the bumper reinforcement, the upper flange portion may be positioned between the impact energy reception-side face and the upper vertical portion and the lower flange portion may be positioned between the impact energy reception-side face and the lower vertical portion.

[0021] In the vehicle bumper structure according to the aspect of the invention described above, at least one of the bumper reinforcement and the energy absorber may be provided with positioning means for determining a longitudinal position of the energy absorber with respect to the bumper reinforcement.

[0022] In this vehicle bumper structure, the longitudinal position of the energy absorber with respect to the bumper reinforcement is determined by the positioning means. Therefore, the energy absorber is precisely fitted to the vehicle or the bumper reinforcement. Also, it is possible to suppress positional displacement of the energy absorber with respect to the bumper reinforcement in the longitudinal direction when a load is applied to the energy absorber. Thus, it is possible to deform the energy absorber in a prescribed manner.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The foregoing and further features and advantages of the invention will become apparent from the following description of example embodiments with reference to the accompanying drawings, wherein the same or corresponding portions will be denoted by the same reference numerals and wherein:

FIG 1 is a longitudinal cross-sectional view showing a front bumper to which a vehicle bumper structure according to a first embodiment of the invention is applied;

FIG 2 is an exploded perspective view showing a partial structure of the front bumper shown in FIG 1; FIG 3 is a side view illustrating the state in which a load is applied to a bumper absorber of the front bumper shown in FIG 1;

FIG 4 is a longitudinal cross-sectional view showing a first modification of a bumper reinforcement that is included in the vehicle bumper structure according to the first embodiment of the invention; FIG 5 is a longitudinal cross-sectional view showing a second modification of the bumper reinforcement that is included in the vehicle bumper structure according to the first embodiment of the invention;

FIG 6 is a longitudinal cross-sectional view showing a third modification of the bumper reinforcement that is included in the vehicle bumper structure according to the first embodiment of the invention;

FIG 7 is a perspective view showing a partial structure of a front bumper to which a vehicle bumper structure according to a second embodiment of the invention is applied;

FIG 8 is an exploded perspective view showing a partial structure of a front bumper to which a vehicle bumper structure according to a third embodiment of the invention is applied;

FIG 9 is a longitudinal cross-sectional view showing a partial structure of a front bumper to which a vehicle bumper structure according to a fourth embodiment of the invention is applied; FIG 10 is a longitudinal cross-sectional view showing a partial structure of a front bumper to which a vehicle bumper structure according to a fifth embodiment of the invention is applied; and

FIG 11 is a longitudinal cross-sectional view showing a fourth modification of the bumper reinforcement that is included in the vehicle bumper structure according to the first embodiment of the invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0024] Hereafter, example embodiments of the invention will be described in detail with reference to the accompanying drawings. First, a first embodiment of the invention will be described. FIG. 1 is a longitudinal cross-sectional view showing a front bumper

10 to which a vehicle bumper structure according to the first embodiment of the invention is applied. FIG 2 is an exploded perspective view showing a partial structure of the front bumper 10. Note that, in the drawings, an arrow FR indicates the forward direction of a vehicle body, an arrow UP indicates the upward direction of the vehicle body, and an arrow W indicates the vehicle-width direction. Note that, the terms "rear" and "front" in this specification mean "front" and "rear" in the longitudinal direction of the vehicle body.

[0025] The front bumper 10 according to the first embodiment of the invention is provided at a front-end lower portion of the vehicle body (not shown) of an automobile and extends in the vehicle-width direction. The front bumper 10 includes a bumper cover 12 which forms part of the exterior appearance of the automobile. The bumper cover 12 is a thin member made of resin material. The bumper cover 12 is fixed to the front-end lower portion of the vehicle body with, for example, screws (not shown). A metal bumper reinforcement (reinforcing member) 14 is provided at the rear of the bumper cover 12.

[0026] The bumper reinforcement 14 is a long rectangular cylinder member that is formed by extruding, for example, aluminum material. The bumper reinforcement 14 is arranged in such a manner that the longitudinal direction of the bumper reinforcement 14 matches the vehicle- width direction. Paired right and left front side members (not shown) are arranged at the rear of the bumper reinforcement 14. The front side members are located in a front portion of the vehicle body, and extend in the longitudinal direction of the vehicle body. The bumper reinforcement 14 is connected to front end portions of these front side members. Inside the bumper reinforcement 14, paired upper and lower ribs rib 14A and 14B are provided. The bumper reinforcement 14 is reinforced by these ribs 14A and 14B.

[0027] In addition, a bumper absorber 16 that serves as an energy absorber is fitted to a front-side face (impact energy reception-side face) of the bumper reinforcement 14. The bumper absorber 16 is formed, for example, by injection-molding resin material. The bumper absorber 16 and the bumper reinforcement 14 are substantially the same in length. The bumper absorber 16 is arranged in such a manner that the longitudinal direction of the bumper absorber 16 matches the longitudinal direction of the bumper reinforcement 14 (vehicle-width direction).

[0028] As shown in FIG. 1, the bumper absorber 16 is formed into a shape having an open cross-section, that is, the bumper absorber 16 opens toward the bumper reinforcement 14. The bumper absorber 16 includes an upper wall portion 16A and a lower wall portion 16B that face each other in the vehicle-height direction, and a vertical wall portion 16C that connects a front end portion of the upper wall portion 16A to a front end portion of the lower wall portion 16B.

[0029] The upper wall portion 16 A is sloped upward toward the rear of the vehicle body, and the lower wall portion 16B is sloped downward toward the rear of the vehicle body. That is, the upper wall portion 16A and the lower wall portion 16B are arranged in such a manner that they are apart more from each other toward the rear of the vehicle body (the distance between the upper wall portion 16A and the lower wall portion 16B of the bumper absorber 16 increases toward the rear of the vehicle body). This structure enhances the efficiency in forming the bumper absorber 16 through injection-molding.

[0030] A flange portion 16D that projects toward the top of the vehicle body is provided at a rear end portion of the upper wall portion 16 A. In addition, a flange portion 16E that projects toward the bottom of the vehicle body is provided at a rear end portion of the lower wall portion 16B. Therefore, the bumper absorber 16 is formed into a shape having a hut-shaped cross-section, and is arranged in such a manner that the flange portions 16D and 16E contact a front wall portion 14C of the bumper reinforcement 14. [0031] Paired projections 18 and 20 that project toward the front of the vehicle body

(toward the bumper absorber 16) are provided on the front wall portion 14C of the bumper reinforcement 14. The projection 18 is formed at a position immediately above the bumper absorber 16 in the vehicle-height direction. The projection 20 is formed at a position immediately below the bumper absorber 16 in the vehicle-height direction. The projections 18 and 20 extend in the longitudinal direction of the bumper reinforcement 14. Each of the projections 18 and 20 continuously extends from one end portion to the other end portion of the bumper reinforcement 14. The projections 18 and 20 are formed when the bumper reinforcement 14 is formed through extrusion. Each of the projections 18 and 20 is formed into a shape having an L-shaped cross-section. [0032] The projection 18 that is formed at a position immediately above the bumper absorber 16 is arranged on the opposite side of the front wall portion 14C of the bumper reinforcement 14 from the rib 14A. The projection 18 includes a horizontal portion 18A that projects from the front wall portion 14C toward the front of the vehicle body, and a vertical portion 18B that projects from the tip of the horizontal portion 18 A toward the bottom of the vehicle body.

[0033] The projection 20 that is arranged immediately below the bumper absorber 16 is arranged on the opposite side of the front wall portion 14C of the bumper reinforcement 14 from the rib 14B. The projection 20 includes a horizontal portion 2OA that projects from the front wall portion 14C toward the front of the vehicle body, and a vertical portion 2OB that projects from the tip of the horizontal portion 2OA toward the top of the vehicle body.

[0034] The flange portion 16D of the bumper absorber 16 is fitted in a space between the vertical portion 18B of the projection 18 and the front wall portion 14C of the bumper reinforcement 14. The flange portion 16E of the bumper absorber 16 is fitted in a space between the vertical portion 2OB of the projection 20 and the front wall portion 14C of the bumper reinforcement 14. Therefore, the flange portions 16D and 16E of the bumper absorber 16 are supported by the projections 18 and 20 of the bumper reinforcement 14, respectively. Thus, the bumper absorber 16 is fitted to the front-side face (impact energy reception-side face) of the bumper reinforcement 14.

[0035] In order to fit the bumper absorber 16 to the bumper reinforcement 14, the flange portions 16D and 16E of the bumper absorber 16 are fitted in the space between the vertical portion 18B and the front wall portion 14C and the space between the vertical portion 2OB and the front wall portion 14C, respectively, at one longitudinal end portion of the bumper reinforcement 14. Then, the bumper absorber 16 is slid toward the other longitudinal end portion of the bumper reinforcement 14.

[0036] Next, the effects of the first embodiment of the invention will be described. In the front bumper 10 structured in the above-described manner, when an object collides with a front-side portion of the bumper cover 12 and an impact load directed toward the rear of the vehicle body, which is equal to or higher than a predetermined value, is applied to the vertical wall portion 16C of the bumper absorber 16 via the bumper cover 12, the upper wall portion 16A and the lower wall portion 16B of the bumper absorber 16 bend, at longitudinal middle portions, in such a manner that the upper wall portion 16A and the lower wall portion 16B are apart more from each other, and the bumper absorber 16 deforms (crushes) toward the bumper reinforcement 14. In this way, impact energy of the object is absorbed.

[0037] In the bumper absorber 16 according to the first embodiment of the invention, the upper wall portion 16A and the lower wall portion 16B are sloped in such a manner that they are apart more from each other toward the rear of the vehicle body in order to enhance the efficiency in forming the bumper absorber 16 through injection-molding. Therefore, as shown in FIG. 3, when an impact load F directed toward the rear of the vehicle body is applied to the vertical wall portion 16C of the bumper absorber 16, component forces fl that proceed in opposite directions are applied to the opening-side end portions of the bumper absorber 16 due to reaction forces f from the bumper reinforcement 14.

[0038] Therefore, the opening-side end portions of the bumper absorber 16 attempt to spread apart in the vehicle-height direction due to the component forces fl. However, according to the first embodiment of the invention, the end of the flange portion 16D of the bumper absorber 16 is pushed against the horizontal portion 18A of the upper projection 18, and the end of the flange portion 16E is pushed against the horizontal portion 2OA of the lower projection 20. Thus, spreading apart of the opening-side end portions of the bumper absorber 16 is prevented. Therefore, according to the first embodiment of the invention, it is possible to prevent or suppress deformation of the bumper absorber 16 in an unexpected manner due to spreading apart of the opening-side end portions of the bumper absorber 16. As a result, it is possible to deform the bumper absorber 16 in a prescribed manner.

[0039] In addition, according to the first embodiment of the invention, each of the projections 18 and 20 of the bumper reinforcement 14 extends continuously from one longitudinal end portion to the other longitudinal end portion of the bumper reinforcement 14. Therefore, it is possible to prevent spreading apart of the opening-side end portions of the bumper absorber 16 at any position of the bumper reinforcement 14 along the longitudinal direction of the bumper reinforcement 14. 5 Therefore, even if an object that is long in the up-and-down direction, for example, a leg of a pedestrian collides with the front-side portion of the bumper cover 12 and a load is applied to a certain portion of the bumper absorber 16 in a concentrated manner, it is possible to prevent spreading apart of the opening-side end portions at the certain portion in the vehicle-height direction.

10 [0040] When a U-shaped energy absorber described in "description of the related art" is used, the energy absorber is fitted to the bumper reinforcement only at some portions with clips or hooks. Therefore, if a load is applied in a concentrated manner to a portion that is apart from the clips or hooks, it is not possible to sufficiently suppress spreading apart of the opening-side end portions of the energy absorber. On the other

15 hand, when a load is applied in a concentrated manner to a portion near a portion at which the energy absorber is fitted to the bumper reinforcement with the clip or the hook, a shearing load is applied to the clip or the hook at this portion, which may arise a possibility that the fitting member such as the clip or the hook will break. In this case as well, it is difficult to sufficiently suppress spreading apart of the opening-side end

20 portions of the energy absorber. Examples of such U-shaped energy absorber include an energy absorber that is fitted to the bumper reinforcement when opening-side end portions hold front end portions of the bumper reinforcement from above and below. However, in this type of energy absorber (bumper absorber), due to its structure, it is not possible to suppress spreading apart of the opening-side end portions when a load is

25 applied thereto.

[0041] In contrast, according to the first embodiment of the invention, it is possible

(_-,__ to prevent spreading apart of the opening-side end portions of the bumper absorber 16 as described above. In addition, even when a load is applied to a certain portion of the bumper absorber 16 in a concentrated manner, spreading apart of the opening-side end portions of the bumper absorber 16 is appropriately prevented by the projections 18 and 20 that extend continuously in the longitudinal direction of the bumper absorber 16.

[0042] In addition, according to the first embodiment of the invention, when the bumper absorber 16 deforms, the end of the flange portion 16D is pushed against the horizontal portion 18A of the projection 18 and the end of the flange portion 16E is pushed against the horizontal portion 2OA of the projection 20, whereby spreading apart of the opening-side end portions of the bumper absorber 16 is prevented. In this case, compressive loads are applied to the flange portions 16D and 16E. Therefore, as compared with the case in which shearing loads are applied to the flange portions 16D and 16E, breakage of the flange portions 16D and 16E (bumper absorber 16) is suppressed effectively.

[0043] In addition, because the projections 18 and 20 extend continuously in the longitudinal direction of the bumper reinforcement 14, the compressive load that is applied between the projection 18 and the flange portion 16D and the compressive load that is applied between the projection 20 and a flange portion 16E are dispersed into a wide region of the bumper reinforcement 14 along the longitudinal direction. Therefore, it is possible to more effectively suppress breakage of the bumper absorber 16.

[0044] In addition, according to the first embodiment of the invention, the flange portions 16D and 16E of the bumper absorber 16 are held by the projections 18 and 20 that are formed integrally with the bumper reinforcement 14, whereby the bumper absorber 16 is fitted to the bumper reinforcement 14. Therefore, an additional component used to fit the bumper absorber 16 to the bumper reinforcement 14 need not be provided, which reduces the number of components.

[0045] According to the first embodiment of the invention, spreading apart of the opening-side end portions of the bumper absorber 16 is prevented by the projections 18 and 20 that project from the front wall portion 14C of the bumper reinforcement 14.

Therefore, it is possible to prevent spreading apart of the opening-side end portions of the bumper absorber 16 with a simple structure.

[0046] In the first embodiment of the invention, spreading apart of the opening-side end portions of the bumper absorber 16 is prevented by the projections 18 and 20 (spreading apart prevention portions) that project from the front wall portion 14C of the bumper reinforcement 14 toward the front of the vehicle body. However, another structure may be employed to implement the invention. For example, as shown in FIG 11, a pair of upper and lower grooves (spreading apart prevention portions) 92B and 92C that extend in the longitudinal direction of a bumper reinforcement 92 may be formed in a front wall portion 92A of the bumper reinforcement 92, and the opening-side end portions of the bumper absorber 16 may be fitted in these grooves 92B and 92C. With this structure as well, it is possible to prevent spreading apart of the opening-side end portions of the bumper absorber 16.

[0047] In the first embodiment of the invention, the projections 18 and 20 are formed integrally with the bumper reinforcement 14. However, another structure may be employed to implement the invention. For example, projections may be formed separately from a bumper reinforcement and then fitted to the bumper reinforcement (this structure are employed in the other embodiments of the invention described below).

[0048] For example, in an example shown in FIG. 4, projections 30 and 32 formed into a shape having a crank-shaped cross-section are connected through, for example, spot-welding to a front wall portion 34A of a bumper reinforcement 34 that is a rectangular cylinder member. In this example, the flange portions 16D and 16E of the bumper absorber 16 (not shown in FIG. 4) are held by projections 30 and 32, respectively, and spreading apart of the opening-side end portions of the bumper absorber 16 is prevented by the projections 30 and 32.

[0049] In addition, in an example shown in FIG 5, a plate 36 is connected to the front wall portion 34A of the bumper reinforcement 34, and projections 36A and 36B having a L-shaped cross-section are provided at an upper end portion and a lower end portion of the plate 36, respectively. In this example as well, the flange portions 16D and 16E of the bumper absorber 16 (not shown in FIG 5) are held by the projections 36A and 36B, respectively, and spreading apart of the opening-side end portions of the bumper absorber 16 is prevented by the projections 36A and 36B. [0050] In an example shown in FIG 6, a main body portion 40 of a bumper reinforcement 38 is formed into a shape having an open cross-section, that is, the main body portion 40 opens toward the front of the vehicle body. Then, the plate 36 is connected to flange portions that are provided at front-end portions of the main body portion 40, whereby the opening of the bumper reinforcement 38 is blocked. In this example as well, the flange portions 16D and 16E of the bumper absorber 16 (not shown in FIG. 5) are held by the projections 36A and 36B of the plate 36, respectively, and spreading apart of the opening-side end portions of the bumper absorber 16 is prevented.

[0051] In addition, in the three examples described above, the bumper reinforcement 34 (or the main body portion 40) and the projections 30 and 32 (or the plate 36) may be produced by methods other than aluminum extrusion. Therefore, flexibility in selecting material for these components and method for producing these components increases.

[0052] Next, other embodiments of the invention will be described. Note that, the same reference numerals will be provided to the structures that are basically the same as those in the first embodiment of the invention, and descriptions on these structures will not be provided below.

[0053] Hereafter, a second embodiment of the invention will be described. FIG. 7 is a perspective view showing a partial structure of a front bumper 50 to which a vehicle bumper structure according to the second embodiment of the invention is applied. The second embodiment of the invention is mostly the same as the first embodiment of the invention except that hook portions 52, which serve as positioning means, are fitted to the bumper absorber 16 at respective longitudinal end portions. Each hook portion 52 is formed into a shape having a substantially L-shaped cross-section, and includes an outward extending portion 52A that extends from the longitudinal end portion of the bumper absorber 16 outward in the vehicle- width direction, and a rearward extending portion 52B that extends from the end of the outward extending portion 52A toward the rear of the vehicle body. One of the rearward extending portions 52B hooks on to one of the longitudinal end portions of the bumper reinforcement 14, and the other rearward extending portion 52B hooks on to the other longitudinal end portion of the bumper reinforcement 14. Thus, the position of the bumper absorber 16 with respect to the bumper reinforcement 14 in the longitudinal direction (vehicle-width direction) is determined.

[0054] According to the second embodiment of the invention, it is possible to precisely fit the bumper absorber 16 to the bumper reinforcement 14, and to suppress displacement of the bumper absorber 16 with respect to the bumper reinforcement 14 in the longitudinal direction when a load is applied to the bumper absorber 16. Thus, it is possible to deform the bumper absorber 16 in a prescribed manner.

[0055] Hereafter, a third embodiment of the invention will be described. FIG 8 is an exploded perspective view showing a partial structure of a front bumper 60 to which a vehicle bumper structure according to the third embodiment of the invention is applied.

The third embodiment of the invention is mostly the same as the first embodiment of the invention except that each of the projections 18 and 20 of the bumper reinforcement 14 is divided into two portions at the midpoint position in the longitudinal direction, and a positioning clearance 62, which serves as positioning means, is formed between the two portions.

[0056] In addition, a positioning projection 64, which forms the positioning means together with the positioning clearance 62, is formed on each of the flange portions 16D and 16E of the bumper absorber 16 at a longitudinal middle portion. The positioning projections 64 are fitted in the positioning clearances 62 when the bumper absorber 16 is fitted to the bumper reinforcement 14. Thus, the bumper absorber 16 is positioned with respect to the bumper reinforcement 14 in the longitudinal direction (vehicle-width direction).

[0057] According to the third embodiment of the invention as well, it is possible to precisely fit the bumper absorber 16 to the bumper reinforcement 14, and to suppress displacement of the bumper absorber 16 with respect to the bumper reinforcement 14 in the longitudinal direction when a load is applied to the bumper absorber 16. Thus, it is possible to deform the bumper absorber 16 in a prescribed manner.

[0058] In the third embodiment of the invention, the positioning projection 64 may be formed on each of the longitudinal end portions of each of the flange portions 16D and 16E. In this case, the positioning projections 64 formed on the respective longitudinal end portions of the flange portions 16D and 16E are fitted to the respective longitudinal end portions of the projections 18 and 20. Thus, the position of the bumper absorber 16 with respect to the bumper reinforcement 14 in the longitudinal direction is determined. In this case, the length of the bumper absorber 16 needs to be greater than the length of the bumper reinforcement 14. However, the positioning clearances 62 described above need not be formed. Therefore, the bumper reinforcement 14 may be produced just through extrusion. Therefore, it is possible to produce the bumper reinforcement 14 more easily.

[0059] Hereafter, a fourth embodiment of the invention will be described. FIG 9 is a longitudinal cross-sectional view showing a partial structure of a front bumper 70 to which a vehicle bumper structure according to the fourth embodiment of the invention is applied. The fourth embodiment of the invention is mostly the same as the first embodiment of the invention except the following features. The bumper absorber 16 is not provided with the flange portions 16D and 16E, and the bumper absorber 16 is fitted to the front wall portion 14C of the bumper reinforcement 14 with fitting members (e.g. clips) (not shown).

[0060] In addition, in the fourth embodiment of the invention, the projections 18 and 20 of the bumper reinforcement 14 are not provided with the vertical portions 18B and 2OB, and rear end portions of the upper wall portion 16A and the lower wall portion 16B of the bumper absorber 16 contact the horizontal portions 18A and 18B of the projections 18 and 20, respectively.

[0061] According to the fourth embodiment of the invention as well, spreading apart of the opening-side end portions of the bumper absorber 16 in the vehicle-height direction is prevented by the projections 18 and 20. Therefore, mostly the same effects as those in the first embodiment of the invention are obtained.

[0062] Hereafter, a fifth embodiment of the invention will be described. FIG. 10 is a longitudinal cross-sectional view showing a partial structure of a front bumper 80 to which a vehicle bumper structure according to the fifth embodiment of the invention is applied. The fifth embodiment of the invention is mostly the same as the first embodiment of the invention except that the structure of a bumper reinforcement 82 differs from the structure of the bumper reinforcement 14 according to the first embodiment of the invention.

[0063] The bumper reinforcement 82 is a rectangular cylinder member, and paired upper projection 82B and lower projection 82C are formed in a front wall portion 82A through pressing or rolling. Each of the projections 82B and 82C is formed into a shape having a U-shaped cross-section, projects from the front wall portion 82A toward the front of the vehicle body, and extends continuously in the longitudinal direction of the bumper reinforcement 82. The bumper absorber 16 that is not provided with the flange portions 16D and 16E as in the fourth embodiment of the invention is provided between the projections 82B and 82C. The rear end portions of the upper wall portion 16A and the lower wall portion 16B of the bumper absorber 16 contact the projections 82B and 82C, respectively. Note that, the shape of the projections 82B and 82C may be changed on an as-required basis. For example, the projections 82B and 82C may be formed into a shape having a U-shaped cross-section.

[0064] According to the fifth embodiment of the invention as well, spreading apart of the opening-side end portions of the bumper absorber 16 is prevented by the projections 82B and 82C. Therefore, mostly the same effects as those in the first embodiment of the invention are obtained.

[0065] In each of the first to fifth embodiments of the invention, the invention is applied to a front bumper of an automobile. Alternatively, the invention may be applied to a rear bumper of an automobile.

Claims

CLAIMS (PCT):

1. A vehicle bumper structure, comprising: an energy absorber (16) that is fitted to an impact energy reception-side face (14C, 34A, 82A, 92A) of a bumper reinforcement (14, 34, 40, 82, 92) for a vehicle, and that opens toward the bumper reinforcement (14, 34, 40, 82, 92); and a spreading apart prevention portion (18, 20; 30, 32; 36A, 36B; 82B, 82C; 92B, 92C) provided to the bumper reinforcement (14, 34, 40, 82, 92) to prevent spreading apart of opening-side end portions of the energy absorber (16) when the energy absorber (16) deforms due to a load that is directed to the bumper reinforcement (14, 34, 40, 82, 92).

2. The vehicle bumper structure according to claim 1, wherein: the spreading apart prevention portion (18, 20; 30, 32; 36A, 36B; 82B, 82C) includes an upper spreading apart prevention portion (18, 30, 36A, 82B) and a lower spreading apart prevention portion (20, 32, 36B, 82C); the upper spreading apart prevention portion (18, 30, 36A, 82B) is formed at a position above the energy absorber (16) in a vehicle-height direction, and extends in a longitudinal direction of the bumper reinforcement (14, 34, 40, 82); and the lower spreading apart prevention portion (20, 32, 36B, 82C) is formed at a position below the energy absorber (16) in the vehicle-height direction, and extends in the longitudinal direction of the bumper reinforcement (14, 34, 40, 82).

3. The vehicle bumper structure according to claim 1 or 2, wherein the opening-side end portions of the energy absorber (16) contact the spreading apart prevention portion (18, 20; 30, 32; 36A, 36B; 82B, 82C; 92B, 92C), whereby spreading apart of the opening-side end portions is prevented.

4. The vehicle bumper structure according to any one of claims 1 to 3, wherein the opening-side end portions of the energy absorber (16) are held by the spreading apart prevention portion (18, 20; 30, 32; 36A, 36B; 82B, 82C; 92B, 92C), whereby the energy absorber (16) is fitted to the bumper reinforcement (14, 34, 40, 82, 92).

5. The vehicle bumper structure according to any one of claims 1 to 4, wherein the spreading apart prevention portion (18, 20; 30, 32; 36A, 36B; 82B, 82C) is formed of a projection (18, 20; 30, 32; 36A, 36B; 82B, 82C) that projects from the impact energy reception-side face (14C, 34A, 82A) of the bumper reinforcement (14, 34, 40, 82) toward the energy absorber (16).

6. The vehicle bumper structure according to claim 2, wherein: the energy absorber (16) includes an upper wall portion (16A) and a lower wall portion (16B) that are sloped so as to be apart more from each other toward the bumper reinforcement (14, 82) and a vertical wall portion (16C) that connects the upper wall portion (16A) and the lower wall portion (16B) to each other; the upper spreading apart prevention portion (18, 82B) and the lower spreading apart prevention portion (20, 82C) are formed integrally with the bumper reinforcement (14, 82); and a bottom face of the upper spreading apart prevention portion (18, 82B) contacts an opening-side end portion of the upper wall portion (16A), and a top face of the lower spreading apart prevention portion (20, 82C) contacts an opening-side end portion of the lower wall portion (16B).

7. The vehicle bumper structure according to claim 2, wherein: the energy absorber (16) is formed of an upper wall portion (16A) and a lower wall portion (16B) that are sloped so as to be apart more from each other toward the bumper reinforcement (34, 40) and a vertical wall portion (16C) that connects the upper wall portion (16A) and the lower wall portion (16B) to each other; the upper spreading apart prevention portion (30, 36A) and the lower spreading apart prevention portion (32, 36B) are attached to the bumper reinforcement (34, 40) in such a manner that the upper spreading apart prevention portion (30, 36A) and the lower spreading apart prevention portion (32, 36B) are immovable relative to the bumper reinforcement (34, 40); and a bottom face of the upper spreading apart prevention portion (30, 36A) contacts an opening-side end portion of the upper wall portion (16A), and a top face of the lower spreading apart prevention portion (32, 36B) contacts an opening-side end portion of the lower wall portion (16B).

8. The vehicle bumper structure according to claim 1, wherein: the energy absorber (16) is formed of an upper wall portion (16A) and a lower wall portion (16B) that are sloped so as to be apart more from each other toward the bumper reinforcement (92) and a vertical wall portion (16C) that connects the upper wall portion (16A) and the lower wall portion (16B) to each other; and the spreading apart prevention portion (92B, 92C) is formed of an upper groove (92B) into which an opening-side end portion of the upper wall portion (16A) is fitted, and a lower groove (92C) into which an opening-side end portion of the lower wall portion (16B) is fitted.

9. The vehicle bumper structure according to claim 6 or 7, wherein: an upper flange portion (16D) that extends upward in the vehicle-height direction is formed at the opening-side end portion of the upper wall portion (16A), and a lower flange portion (16E) that extends downward in the vehicle-height direction is formed at the opening-side end portion of the lower wall portion (16B); the upper spreading apart prevention portion (18, 30, 36A) includes an upper horizontal portion that extends from the impact energy reception-side face (14C, 34A) of the bumper reinforcement (14, 34, 40) outward in a longitudinal direction of a vehicle body and an upper vertical portion that extends from a tip of the upper horizontal portion downward in the vehicle-height direction, and the lower spreading apart prevention portion (20, 32, 36B) includes a lower horizontal portion that extends from the impact energy reception-side face (14C, 34A) of the bumper reinforcement (14, 34, 40) outward in the longitudinal direction of the vehicle body and a lower vertical portion that extends from a tip of the lower horizontal portion upward in the vehicle-height direction; and when the energy absorber (16) is fitted to the bumper reinforcement (14, 34, 40), the upper flange portion (16D) is positioned between the impact energy reception-side face (14C, 34A) and the upper vertical portion and the lower flange portion (16E) is positioned between the impact energy reception-side face (14C, 34A) and the lower vertical portion.

iθ. The vehicle bumper structure according to any one of claims 1 to 9, wherein at least one of the bumper reinforcement (14, 34, 40, 82, 92) and the energy absorber (16) is provided with positioning means (52, 62, 64) for determining a longitudinal position of the energy absorber (16) with respect to the bumper reinforcement (14, 34, 40, 82, 92).