JP4515388B2 - Aluminum alloy door beam and automobile door structure - Google Patents

Description

  The present invention relates to an aluminum alloy door beam used as an automobile door reinforcing member and an automobile door structure.

  The following Patent Document 1 is made of an aluminum alloy extruded material, and in a cross section perpendicular to the longitudinal direction, as shown in FIG. And a door beam in which the center line a of the compression side flange 1 and the center line b of the tension side flange 2 are shifted is described. The center lines a and b are lines drawn in the direction of the load P through the center (length center) of each flange in a cross section perpendicular to the longitudinal direction. Since both the flanges 1 and 2 of the door beam in FIG. 2 have a uniform thickness and are parallel to each other, the directions of the center lines a and b are perpendicular to the flanges 1 and 2.

  This door beam has a load acting line (in the same position as the center line a of the compression side flange 1 and indicated by an arrow) when it is assumed that the load P is evenly applied to the compression side flange 1 and the center line b of the tension side flange. Due to the deviation, when subjected to a bending load P, the beam cross-section is likely to buckle (the web collapses) so that the load is greatly reduced before the strain is accumulated on the tension side as cracking occurs. As a result, as described in the above publication, the load on the tension side flange 2 is relaxed, cracks are less likely to occur on the tension side, and cracks are less likely to occur on the compression side. Thereby, the breaking displacement can be greatly improved, a large breaking displacement can be obtained even with a short beam length, and the necessary maximum load and energy absorption amount can be obtained without increasing the weight at the same time.

Japanese Patent Laid-Open No. 11-278054

For door beams, the flange and the outer panel of the door may be bonded at one or more locations via an adhesive to improve rigidity, prevent vibration and noise, etc., but since the flange is not curved, the curved outer There is a disadvantage that the gap with the panel is not constant and it is difficult to adhere. The first object of the present invention is to improve this point.
Further, when the actual load direction is obliquely deviated from the assumed direction (parallel to the center lines a and b), there is a problem that the flange cannot receive the load vertically. Another object of the present invention is to improve this point.

The aluminum alloy door beam according to the present invention is made of an aluminum alloy extruded material in which a pair of flanges are connected by a pair of webs, and the compression side flange is curved outward when viewed in a cross section perpendicular to the longitudinal direction. Features.
Further, the aluminum alloy door beam according to the present invention is made of an aluminum alloy extruded material in which a pair of flanges are connected by a pair of webs, and when viewed in a cross section perpendicular to the longitudinal direction, the compression side flange is curved outward. The curvature is matched to the curvature of the outer panel of the door.
Further, the aluminum alloy door beam according to the present invention is made of an aluminum alloy extruded material in which a pair of flanges are connected by a pair of webs, and when viewed in a cross section perpendicular to the longitudinal direction, the compression side flange is curved outward, The gap with the outer panel is substantially constant.
The inside of the door beam and the outer panel can be bonded with an adhesive at one or more places.

  In the case of the door beam of the present invention, based on the fact that the compression side flange is curved outward in the cross section perpendicular to the longitudinal direction, the gap and the outer panel are made constant by combining the curvature with the curved outer panel. There is an advantage that it is easy to bond with the adhesive. Further, even when the actual load direction is obliquely deviated from the assumed direction, there is an advantage that the flange can receive the load vertically.

FIG. 1 shows an example of a door beam (cross section perpendicular to the longitudinal direction). This door beam is made of an aluminum alloy extruded material in which a pair of flanges 11 and 12 are connected by a pair of webs 13 and 14, and both the flanges 11 and 12 are parallel to each other and have the same thickness (c = d) and the same width (e = f), and both webs 13, 14 are perpendicular to both flanges and have the same thickness (g = h) and the same length. Further, in the cross section perpendicular to the longitudinal direction, both overhanging widths e ₁ and e ₂ of the flange 11 are equal to both overhanging widths f ₁ and f ₂ of the flange 12 (e ₁ = f ₁ , e ₂ = f _2). ), The center line a of the flange 11 and the center line b of the flange 12 are shifted to the left and right. The center lines a and b are straight lines drawn through the centers (length centers) of the flanges 11 and 12 in the direction of the load P, and are perpendicular to the flanges 11 and 12.
The fact that both the center lines a and b are shifted to the left and right means that they are asymmetric with respect to both the neutral axis i of bending and the axis j passing through the centroid O and perpendicular to the neutral axis i of bending. . The sectional shape of the door beam is symmetric with the centroid O as the center of symmetry in a cross section perpendicular to the longitudinal direction. In other words, the same shape is obtained even when the centroid O is rotated by 180 ° around the centroid O.

As in the door beam shown in FIG. 5, in the cross-sectional shape, the widths of the flanges 1 and 2 are different (e ≠ f), and the overhanging widths are different (e ₁ ≠ f ₁ , e ₂ ≠ f ₂ ), or when the cross-sectional shape is not symmetrical about the centroid O, such as when the thickness is different (c ≠ d), as shown in FIG. 4 (a), (1) first perpendicular to the cross section of the extruded material Cut to a predetermined length at the surface A, and then cut both ends of each extruded material at the oblique surfaces B and C, or (b) only the oblique surfaces B and C without cutting at the vertical surface A A method such as cutting with is adopted. However, in either method, the portion indicated by dots in FIG. 4A becomes a yield drop (a portion not used for a product), and the yield is lowered.

On the other hand, as shown in FIG. 4B, the door beam shown in FIG. 1 has a surface B (of the flanges 11 and 12 in the cross section) inclined with respect to the longitudinal direction of the long aluminum alloy extruded material having the above cross section. The width of the door beam along the longitudinal direction of the extruded material on the surface C having the smallest width) and the surface C inclined oppositely to the surface B (similarly, the surface having the smallest width of the flanges 11 and 12 in the cross section). Cut alternately every time. In this extruded material, the direction of the intersecting line where the surfaces B and C intersect with the flange surfaces of the extruded material (surfaces of the flanges 11 and 12) is perpendicular to the longitudinal direction of the extruded material.
The cross-sectional shape of the extruded material is symmetric about the centroid O in the cross-section perpendicular to the longitudinal direction, so that each of the cut extruded materials 21, 22, 23, 24. It has a shape and can be used as it is as a door beam, with little yield loss. Further, according to this manufacturing method, the number of cutting steps is reduced, and productivity is improved.

FIG. 2 shows another example of a door beam (also a cross section perpendicular to the longitudinal direction). This door beam is made of an aluminum alloy extruded material in which a pair of flanges 31 and 32 are connected by a pair of webs 33 and 34. Both flanges 31 and 32 are parallel to each other and have the same thickness (c = d) and the same width (e = f), and both webs 33 and 34 are parallel to each other, inclined in the same direction with respect to both flanges, and have the same thickness (g = h) and the same length. Further, in the cross section perpendicular to the longitudinal direction, both overhanging widths e ₁ and e ₂ of the flange 31 are made equal to both overhanging widths f ₁ and f ₂ of the flange 32 (e ₁ = f ₁ , e ₂ = f _2). ), The center line a of the flange 31 and the center line b of the flange 32 are shifted to the left and right. The center lines a and b are perpendicular to the flanges 31 and 32.

The cross-sectional shape of the door beam is asymmetric with respect to the bending neutral axis i and the axis j passing through the centroid O and perpendicular to the bending neutral axis i. The sectional shape of the door beam is symmetric with the centroid O as the center of symmetry in a cross section perpendicular to the longitudinal direction. In other words, the same shape is obtained even when the centroid O is rotated by 180 ° around the centroid O.
In addition, this door beam can also be manufactured by cutting a long aluminum alloy extruded material having the cross-sectional shape as shown in FIG.

FIG. 3 shows an example of a door beam according to the present invention (also a cross section perpendicular to the longitudinal direction). This door beam is made of an aluminum alloy extruded material in which a pair of flanges 41 and 42 are connected by a pair of webs 43 and 44, and differs from the door beam shown in FIG. 1 in that both flanges 41 and 42 are curved.
However, like the door beam shown in FIG. 1, both flanges 41 and 42 have the same width and thickness, and both webs are parallel to each other and have the same length and thickness, and in a cross section perpendicular to the longitudinal direction of the extruded material. The center line a of the flange 41 and the center line b of the flange 42 are shifted left and right. The center lines a and b are parallel to the webs 43 and 44, respectively. The cross-sectional shape is asymmetric with respect to an axis j passing through the bending neutral axis i and the centroid O and perpendicular to the bending neutral axis i, and is symmetric with respect to the centroid O as the center of symmetry. In other words, the same shape is obtained even if rotated 180 ° about the centroid O.
As shown in FIG. 4B, this door beam can also be manufactured by cutting a long aluminum alloy extruded material having the above cross-sectional shape.

  In this door beam, the flanges 41 and 42 are curved outward. Therefore, if the curvature is matched to the curvature of the outer panel of the door, when the inner side of the flange and the outer panel is bonded with an adhesive (increase in rigidity, vibration In some cases, the flange and the outer panel may be bonded in advance through one or more locations to prevent noise, etc.), and since the gap is substantially constant, it is easy to bond. In this case, in order to enhance the adhesiveness between the adhesive and the door beam, the door beam can be appropriately subjected to surface treatment or the like. Examples of the surface treatment include alumite treatment and formation of a hydrated oxide film. Further, since the flanges 41 and 42 are curved, even when the actual load direction is slightly inclined from the assumed direction (parallel to the center lines a and b), the flange receives the load vertically. be able to.

  Various aluminum alloys can be applied to the door beam according to the present invention. In particular, Al—Zn— containing Zn: 4 to 9% (mass%, the same applies hereinafter) and Mg: 0.8 to 2%. An Mg-based aluminum alloy, an Al-Mg-Si-based aluminum alloy containing Mg: 0.4 to 1.3%, Si: 0.2 to 1.5% is preferable. As a general alloy, for example, 7N01 , 6061, 6063, 6N01 and the like.

It is the cross-sectional shape of a door beam. It is another cross-sectional shape of a door beam. It is a cross-sectional shape of the door beam which concerns on this invention. It is a method of manufacturing a door beam by cutting an extruded material, and the left figure is a side view of each. It is the cross-sectional shape of a door beam.

Explanation of symbols

1 Compression side flange 2 Tension side flange 3, 4, 13, 14, 33, 34, 43, 44 Web 11, 12, 31, 32, 41, 42 Flange a, b Center line O Centroid

Claims (2)

In the door beam installed inside the outer panel of the automobile door, a pair of flanges are made of extruded aluminum alloy connected by a pair of webs parallel to each other. An aluminum alloy door beam characterized in that it is curved to match the curvature of the outer panel of the door. In the door beam installed inside the outer panel of the automobile door, a pair of flanges are made of extruded aluminum alloy connected by a pair of webs parallel to each other. The aluminum alloy door beam is characterized in that the gap between the outer panel and the outer panel is substantially constant.

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