JP4267939B2 - Bumper reinforcement - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bumper reinforcing material that is supported on a vehicle body member by a support member that is joined to the inside of the front surface with an open cross-sectional structure including a front surface, an upper surface, and a lower surface.
[0002]
[Prior art]
The bumper reinforcement that is supported on the body member by the support member with an open cross-sectional structure consisting of the front, top and bottom surfaces is simple in structure, easy to change the design according to the vehicle weight, and can reduce the material cost. There are advantages. Such bumper reinforcements sometimes join support members to the edges of the upper surface and the lower surface (Patent Document 6), but in many cases, support members are joined to the inside of the front surface, and bumper reinforcements are attached to the body members. Supported (Patent Documents 1 to 5).
[0003]
[Patent Document 1]
JP 2001-047952 A (2-5 pages, FIG. 1 and FIG. 2)
[Patent Document 2]
Japanese Patent Laid-Open No. 2001-088634 (pages 6-7, FIGS. 14-17)
[Patent Document 3]
US Pat. No. 3,146,014 (pages 3-4, FIGS. 1-3)
[Patent Document 4]
US Pat. No. 3,998,485 (page 3-4, FIG. 1)
[Patent Document 5]
German Patent Application Publication No. 10002379 (2 pages, Fig. 1)
[Patent Document 6]
German Patent Application Publication No. 10100875 (2 pages, FIGS. 1 to 4)
[0004]
[Problems to be solved by the invention]
A point to keep in mind when using the bumper reinforcement is to make the best use of the strength of the bumper reinforcement itself, and this does not change even when the bumper reinforcement has an open sectional structure. However, when the support member is joined to the inside of the front surface of the open section structure, when receiving an impact from the front of the front surface, the upper surface and the lower surface are folded inward in the vertical direction centering on the joint point (folded inward), There is a problem that the strength of the bumper reinforcing material is rapidly reduced (see FIG. 5).
[0005]
As a means for solving the problem of the internal folding, for example, there is a measure for attaching a bulkhead, which is a partition connecting the upper surface and the lower surface inside, to the bumper reinforcement. However, the countermeasure using the bulkhead newly introduces problems such as an increase in the number of parts, an increase in weight, and an increase in material cost and assembly cost.
[0006]
Further, when the support member also serves as an impact absorbing device, the folded upper and lower surfaces may interfere with the supporting member, and the supporting member may not exhibit the impact absorbing performance. For example, when the support member is a multistage tubular structure and the front stage is an impact absorbing device that absorbs impact energy by plastic deformation immersing in the rear stage, the folded upper and lower surfaces inhibit plastic deformation, or the upper and lower surfaces May interfere with the level difference between the front and rear stages and hinder the previous stage immersion.
[0007]
To solve the problem caused by the internal folding of the upper surface or the lower surface, it can be solved by increasing the cross section of the bumper reinforcement. However, this causes an increase in the weight of the bumper reinforcement and reduces the passage area of the cooling air taken into the engine. Will cause problems. Although measures such as cutting away only the interfering part and joining a member having a structure that does not interfere separately are conceivable, the strength balance is difficult, which is disadvantageous in terms of weight and cost increase. Accordingly, a bumper reinforcing material having an open cross-section structure that does not hinder the impact absorbing performance of the supporting member when the supporting member also serves as an impact absorbing device when the impact is applied and the supporting member also serves as an impact absorbing device has been studied.
[0008]
[Means for Solving the Problems]
As a result of the study, the product developed was an open cross-sectional structure consisting of a front surface, an upper surface, and a lower surface, and the upper or lower surface corresponding to the vertical direction of the support member in the bumper reinforcement supported by the support member joined to the inside of the front surface. Is a bumper reinforcing material having a bulging surface formed on the upper surface or the lower surface by expanding the edge of the upper portion in the vertical direction. “The edge of the upper surface or the lower surface in the vertical direction of the support member” refers to the edge of the upper surface or the lower surface that intersects the axis of the support member in the horizontal plane, and the bulging surface moves up and down within the range including the axis. A bulging surface is formed by expanding outward in the direction.
[0009]
The bumper reinforcing material of the present invention prevents the internal folding by partially increasing the rigidity within a range including the axis of the support member by the bulging surface formed on the upper surface or the lower surface. Moreover, even if it folds inward, the extent of the internal fold is relieved so that it may not fold more than the upper surface or the lower surface before the bulging surface is formed by preliminarily expanding outward in the vertical direction. When the degree of inward folding is different between the upper surface and the lower surface, a bulging surface may be formed only on either the upper surface or the lower surface, but it is usually desirable to form a pair of mirror-symmetric bulging surfaces on both the upper surface and the lower surface. .
[0010]
Here, the support member that supports the bumper reinforcing member of the present invention with respect to the vehicle body member may be a member made of a simple bar, a plate, or a combination thereof. However, since it has a function of preventing or mitigating internal folding of the upper surface or the lower surface, when it is a support member that also serves as an impact absorbing device that compresses in the axial direction by plastic deformation that immerses the front stage of the multistage tube into the rear stage, The present invention is particularly effective.
[0011]
Specifically, the bulging surface includes (a) an edge of an upper surface or a lower surface that intersects with the axis of the support member in a horizontal plane, and is formed on the upper surface or the lower surface by expanding symmetrically about the axis. ) It is preferable that the edge of the upper surface or the lower surface is expanded outward in the vertical direction in an arc shape having a center on a vertical line orthogonal to the axis of the support member. That is, the bulging surface is preferably formed at least horizontally with respect to the support member in the horizontal plane (said (a)), and further, the edge portion so that there is no difference in the distance from the support member to the edge portion of the bulge surface. May be formed by expanding ((b) above).
[0012]
Since such a bulging surface is formed by expanding a part of an originally flat upper surface or lower surface outward in the vertical direction, it is constituted by a surface that is not the same surface as the upper surface or the lower surface. From this, a part of the upper surface or the lower surface is displaced in the direction perpendicular to the plane to form a stepped side surface, and a bulging surface parallel to the upper surface or the lower surface can be formed. An exit surface may be formed. In the latter case, the bulging surface has a downward slope from the edge toward the extending direction of the front surface, upper surface, or lower surface.
[0013]
In addition, the bulging surface prevents or alleviates the internal folding of the upper surface or the lower surface, but preferably it is possible to prevent the internal folding. Therefore, the bulging surface may be formed by expanding the edge of the upper surface or the lower surface on which the flange is formed, outwardly in the vertical direction including the flange. The flange may be inward or outward in the vertical direction, but from the viewpoint of avoiding buffering with the support member as much as possible, a flange that is outward in the vertical direction that is away from the support member is preferable. Further, the flange may be provided at the edge of the range where the bulging surface is formed, but it is preferably provided continuously over the entire edge of the upper surface or the lower surface, more preferably the edge over the range where the bulging surface is formed. Good. The bulging surface formed by expanding including the flange has increased rigidity and makes it difficult to fold the upper surface or the lower surface.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an assembled state of a bumper reinforcing member 1 according to the present invention, FIG. 2 is an axial sectional view of a supporting member 2 of the bumper reinforcing member 1, and FIG. FIG. 4 is a rear view seen from the side 2, FIG. 4 is a cross-sectional view corresponding to FIG. 2 of the bumper reinforcing material 1 showing a state in which an impact F is applied to the front surface 3 of the bumper reinforcing material 1, and FIG. FIG. 5 is a cross-sectional view corresponding to FIG. 4, showing a state in which an impact F is applied to the front surface of a bumper reinforcing material (conventional bumper reinforcing material) 4 having an open cross-sectional structure.
[0015]
As shown in FIGS. 1 to 3, the bumper reinforcing member 1 of this example has an open cross-sectional structure composed of a front surface 3, an upper surface 5, and a lower surface 6, and vertically extends to the edges 7 and 8 of the upper surface 5 and the lower surface 6. The outward flanges 9 and 9 are formed over the entire extending direction of the bumper reinforcing material 1 (in FIG. 1, the bumper reinforcing material extends to the back of the drawing but is not shown). The bumper reinforcing material 1 is formed by roll forming from a single original plate, first of all, a basic cross-sectional shape without a bulging surface (C-shaped channel structure of cross section) is formed, and subsequently, bulging surfaces 10 and 10 are formed by press molding.
[0016]
The support member 2 of this example also serves as an impact absorbing device having a two-stage tube structure including a small tube body 11 at the front stage and a large tube body 12 at the rear stage. This support member 2 is subjected to plastic deformation in which the small tubular body 11 at the front stage is immersed in the large tubular body 12 at the rear stage due to the impact received by the bumper reinforcing member 1 so that it sag inward from the step 13 to the large tubular body 12. The shock energy is absorbed by raising and compressing in the axial direction (the arrangement direction of the small tube body 11 and the large tube body 12).
[0017]
The support member 2 is welded with a support member front end (small tube front end) 14 in contact with the inside of the front surface 3, and an auxiliary cover 15 that substantially expands the cross-section of the support member front end 14 is attached to the support member front end 14. The front peripheral edge 16 of the auxiliary cover 15 is welded to the front surface 3 of the bumper reinforcing member 1, and the side peripheral edge 17 is welded to the side surface of the small tubular body 11. Further, the support member rear end (large tube rear end) 18 is in contact with and welded to the support receiving surface 20 provided at the front end of the vehicle body member 19.
[0018]
The bulging surfaces 10 and 10 of the present example are on the vertical line perpendicular to the axis and symmetrical with the edges 7 and 8 of the upper surface 5 and the lower surface 6 intersecting the axis of the support member 2 in the horizontal plane. In the shape of a circular arc having a center at the center, it is formed to expand outward in the vertical direction including the flanges 9 and 9. The bulging surfaces 10 and 10 formed in this way have a semicircular shape in a plan view and are curved surfaces with the highest edge portions 7 and 8 on the axis of the support member 2.
[0019]
When an impact F is applied to the front surface 3 of the bumper reinforcement 1 from the front (for example, a full vehicle collision), the impact F is transmitted from the bumper reinforcement 1 to the support member 2 as shown in FIG. The bumper reinforcement 1 is moved backward by the small tube 11 of the support member 2 being immersed in the large tube 12. At this time, when the impact F applied to the front surface 3 of the bumper reinforcing material 1 is viewed in detail, the impact F is transmitted as it is to the support member 2 in the vicinity of the middle in the vertical direction, but the middle in the upper and lower stages. An impact F is applied in the inward direction, and the upper surface 5 and the lower surface 6 are folded inwardly with the bent edges 21 and 21 with respect to the front surface or the front peripheral edge 16 of the auxiliary cover 15 as an axis (indicated by white arrows in FIG. 4). reference).
[0020]
Here, if the upper surface 5 and the lower surface 6 do not have a bulging surface, as shown in FIG. 5, the upper surface 5 and the lower surface 6 are largely folded inward, and the large tubular body 12 of the support member 2 has an edge of the upper surface 5 and the lower surface 6. The portions 7, 8 or the flanges 9, 9 interfere (in FIG. 5, the distance L between the edge portions 7, 8 of the folded upper surface 5 and lower surface 6 <the outer diameter D of the large tubular body 12), and the bumper reinforcement 1 Limiting retreat. However, if the bulging surfaces 10 and 10 are formed on the upper surface 5 and the lower surface 6 as in the present invention, the bulging surfaces 10 and 10 partially increase the rigidity of the upper surface 5 and the lower surface 6, and Inward folding can be prevented or alleviated (in FIG. 4, the distance L between the edge portions 7 and 8 of the upper surface 5 and the lower surface 6 that is folded inward> the outer diameter D of the large tubular body 12). Thereby, the rapid strength fall at the time of the impact application in the bumper reinforcing material 1 having an open cross-sectional structure can be prevented.
[0021]
Further, since the bulging surfaces 10 and 10 are formed so as to expand away from the support member 2, even if the inner fold is large, the edges 7 and 8 of the upper surface 5 and the lower surface 6 or the flanges 9 and 9. Is less likely to interfere with the large tube 12. In particular, in this example, since the flanges 9 and 9 provided on the edges 7 and 8 of the upper surface 5 and the lower surface 6 are both outward in the vertical direction, the bulging surfaces 10 and 9 are directed toward the support member 2 (particularly the large tube 12). Tolerance that 10 can be folded in is large. Thus, the bumper reinforcing material 1 of the present invention firstly prevents or alleviates the internal folding of the upper surface 5 or the lower surface 6, and secondly avoids interference to the support member 2 due to the internal folding as much as possible. The problem of inward folding in the bumper reinforcement 1 having an open cross-sectional structure is solved.
[0022]
6 is a cross-sectional view corresponding to FIG. 2 of the bumper reinforcement member 22 provided with the bulging surface 10 only on the upper surface 5, and FIG. 7 is a cross-sectional view corresponding to FIG. 2 of the bumper reinforcement member 23 provided with the bulging surface 10 only on the lower surface 6. FIG. 9 is a cross-sectional view corresponding to FIG. 2 of the bumper reinforcing member 25 in which the flanges 24, 24 provided on the edges 7, 8 of the upper surface 5 and the lower surface 6 are inward in the vertical direction, and FIG. 5 is a perspective view corresponding to FIG. 1 showing an assembled state of the bumper reinforcing material 27 formed on the lower surface 6 and the lower surface 6. FIG.
[0023]
The bulging surfaces in the present invention are preferably provided on the upper surface and the lower surface, respectively, and the bulging surfaces are preferably symmetrical with respect to the axis of the support member, and are mirror surfaces in the vertical direction. However, depending on the specifications and required performance of the bumper reinforcement, for example, the bulging surface 10 is provided only on the upper surface 5 as seen in FIG. 6, or the bulging surface 10 is provided only on the lower surface 6 as seen in FIG. Also good. In each of the above examples, the lower surface 6 (or the upper surface 5) is relatively shorter than the upper surface 5 (or the lower surface 6), and there are few adverse effects (such as interference with the support member 2) due to internal folding. There is no bulging surface.
[0024]
In the bumper reinforcing member 1 of the above example (FIGS. 1 to 4), the flanges 1 and 8 and the flanges 7 and 8 on the lower surface 6 are vertically outwardly flanged in order to improve the rigidity of the bumper reinforcing member 1 itself and the bulging surface. 9,9 are provided. Here, when the support member 2 also serves as an impact absorbing device, it is necessary to avoid interference between the flanges 9 and 9 of the bumper reinforcement 1 that has been retracted by the impact and the support member 2 (particularly the large tube 12). 9 are preferably outward in the vertical direction. In other words, if the support member is not an impact absorbing device or if the support member 2 is an impact absorbing device and interference does not become a problem, as shown in FIG. It can also be provided.
[0025]
In addition, since the bulging surface only needs to be composed of a surface that is not continuous with the upper surface or the lower surface, the bulging surface is composed of an inclined plane composed of a pyramidal side surface with the edge on the axis of the support member as a vertex instead of the bulging surface composed of a curved surface. It can also be a bulging surface. Furthermore, as seen in FIG. 9, 26 and 26 may be formed on the upper surface 5 and the lower surface 6 in the form of trapezoidal bulges 26 in a plan view surrounded by stepped side surfaces 28 and 28, respectively. The trapezoidal bulging surface 26 in a plan view is formed by extruding the upper surface 5 and the lower surface 6 intersecting the axis of the support member 2 in a horizontal plane with line symmetry about the axis and outward in the vertical direction toward the upper and lower mirror surfaces. is doing.
[0026]
【The invention's effect】
According to the present invention, the upper or lower surface of the bumper reinforcing material having an open cross-sectional structure is prevented or alleviated, and firstly, a sudden strength reduction at the time of applying an impact is prevented, and secondly, the bumper reinforcing material is a support member or the like. Interference with other members can be avoided. The bumper reinforcing material of the present invention has no change in strength balance, and almost no increase in weight and cost, as compared with a conventional bumper reinforcing material having an open cross-sectional structure. However, there is a great effect in that the problem due to the internal folding of the upper surface or the lower surface can be solved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an assembled state of a bumper reinforcing material according to the present invention.
FIG. 2 is an axial sectional view of a support member of the bumper reinforcing material.
FIG. 3 is a rear view of the bumper reinforcing member as viewed from the support member side.
FIG. 4 is a cross-sectional view corresponding to FIG. 2 of the bumper reinforcing material showing a state in which an impact F is applied to the front surface of the bumper reinforcing material.
5 is a cross-sectional view corresponding to FIG. 4 illustrating a state in which an impact F is applied to the front surface of a bumper reinforcing member having an open cross-sectional structure that does not form a bulging surface.
FIG. 6 is a cross-sectional view corresponding to FIG. 2 of a bumper reinforcing member provided with a bulging surface only on the upper surface.
FIG. 7 is a cross-sectional view corresponding to FIG. 2 of a bumper reinforcing member provided with a bulging surface only on the lower surface.
FIG. 8 is a cross-sectional view corresponding to FIG. 2 of a bumper reinforcing material in which flanges provided at the edges of the upper surface and the lower surface are inward in the vertical direction.
FIG. 9 is a perspective view corresponding to FIG. 1 showing an assembled state of a bumper reinforcing material in which another bulging surface is formed on the upper surface and the lower surface.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bumper reinforcement 2 Support member 3 Bumper reinforcement front 5 Bumper reinforcement top 6 Bumper reinforcement bottom 7 Bumper reinforcement top edge 8 Bumper reinforcement bottom edge 9 Flange
10 Swelling surface

Claims (4)

In bumper reinforcement with an open cross-sectional structure consisting of a front surface, an upper surface, and a lower surface, and supported by a vehicle body member by a support member joined to the inside of the front surface, the edge of the upper surface or the lower surface corresponding to the vertical direction of the support member is directed outward in the vertical direction. A bumper reinforcing material that is expanded to form a bulging surface on an upper surface or a lower surface. 2. The bumper reinforcing material according to claim 1, wherein the bulging surface is formed on an upper surface or a lower surface by expanding an edge of an upper surface or a lower surface intersecting with an axis of the support member in a horizontal plane so as to be symmetrical with respect to the axis. The bumper reinforcing material according to claim 1, wherein the bulging surface is formed by expanding an edge of the upper surface or the lower surface outward in the vertical direction in an arc shape having a center on a vertical line orthogonal to the axis of the support member. The bumper reinforcing material according to claim 1, wherein the bulging surface is formed by expanding an edge of an upper surface or a lower surface on which a flange is formed, to expand outward in the vertical direction including the flange.

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